The only option available to you as you start the game for the very first time will be Mania Mode, which is how you play the game's main story. You can choose which character you want to play as, with the options being Sonic, Tails, Sonic and Tails together, & Knuckles. On your first time through, it'd be a good idea to go with Sonic and Tails; Tails will be controlled by the AI, and although he may at some times fumble around, he can really pitch in during boss fights. Mighty and Ray are also available with the Encore DLC, but your first time through should really be with one of the base game characters.
Many Acts and Zones in the game, like in previous Sonic titles, will be a lot more "open" than others. Despite this, SEGA is still able to create an easily-traversable level from these, so you really shouldn't have too much trouble with any one stage of the game. The only time you might find yourself in a tough spot is the twelfth Zone, but after becoming familiar with it, it'll be just as easy to you as the rest. If you end up losing all your lives when playing the game, you'll start from the beginning of Act 1 of the Zone your game ended in. For example, if you lose your last life in Chemical Plant Zone (Act 2), you'll continue the game from Act 1 of that Zone.
After the events of Sonic & Knuckles, Angel Island has plummeted into the ocean once again due to a massive energy reading. Sonic and Tails will be riding towards Angel Island on Tails' plane after, only to discover that Eggman's five new mechs, the Hard-Boiled Heavies, have gotten to it first. A giant claw extracts the energy source, the Phantom Ruby, out of the ground, creating a rift in time and space. All of the characters present are then warped to Green Hill Zone, where the first piece of the story takes place. The Hard-Boiled Heavies, altered by the Phantom Ruby, have now gained consciousness alongside massive upgrades to their metallic bodies. As they leave, you'll gain control of Sonic and start your adventure. If you start the story as Knuckles, you'll see him get hit by the Heavies as they fly off with the Ruby, sending him to the underground caverns of Green Hill Zone.
Green Hill Zone
As the first Act of the game, Act 1 of Green Hill Zone will be a very easy and straight-forward level. Just continue moving to the right and make sure you have some rings on you to make sure you don't die. Near the end of the level, you'll see a giant ring hovering in a cave, just past a collapsing floor. Heading over there quickly and jumping inside the ring will give you the opportunity to get a Chaos Emerald, although you'll be able to get them all once you beat the game. More information on how the Special Stages and Chaos Emeralds work is on the Extras page. Whether or not you manage to get this emerald, drop down below and head left to pass through a small tunnel, and keep going to the right once more to reach this Act's boss.
Twin Death Eggs, much smaller than the real thing, will be waiting for you at the end of this Act. The lower one will first swing from side to side as the upper one protects itself with spikes; after a while, they'll switch their vulnerability as the lower Death Egg protects itself. Once they get tired of this, the two of them will become invulnerable together and spin in the center of the stage. The key to beating these two is to jump up and hit them when they're open for attack. Each Death Egg is only capable of taking three hits each, and after the first one is defeated, the remaining one will take up a new strategy. It'll rise up in the air, harden, and then bounce along the ground. Just position yourself in an area where the Death Egg will hop right over you, and then strike after its spikes disappear. Once both machines are defeated, a spinning signpost will drop from above. If you want to get more points, you can continue hitting it for a while, but if you wanted to get a trophy out of the way now, you could try making the signpost hit two specific areas in the ground. Make it hit the ground underneath the two purple flowers to the left, as well as underneath the yellow flower to the right, to make two item containers appear. If you can't figure it out now, don't worry, you can always come back to it later.
If you're familiar with the original Sonic the Hedgehog game, you should have been just as familiar with the first Act of Green Hill Zone here. The second Act, however, uses more new material and is far less influenced by designs from the original Green Hill Zone. Ziplines will be scattered all across the area, and your speed on them depends how fast you are when you grab the handle. If you manage to end up behind a waterfall and find a Fire Shield container, open it and head to the left to burn that spiky wooden bridge you would have crossed to get there. Doing this will get another trophy out of the way for you. Since it's that easy to get this trophy, you don't really need to do it now, so don't make this miscellaneous task your main focus.
The final boss of Green Hill Zone will be none other than one of Eggman's many Death Egg Robots, piloted by Eggman himself. As it chases you to the right, a target will appear over you. If you're too far away, Eggman will launch a little bomb towards that spot, but if you're close enough, one of the robot's metal arms will extend in an attempt to hit you. You can jump on the arms to reach the body of the machine and hit it, or you can hit the body from a high ledge when they appear. This machine will be able to take eight hits before being defeated. Even without the ten-minute time limit, the boss battle will end after a few minutes if you're stalling too long, as the ground will just stop appearing as a punishment for being so slow. This really shouldn't be an issue, though, because you shouldn't be taking that long if you have at least a small idea of what to do.
After defeating Eggman, Sonic and Tails will drop down to where his robot crashed to find him angrily commanding the Hard-Boiled Heavies to attack you. After they run off to find some good positions elsewhere, Eggman will take the Phantom Ruby and use it to send you to another familiar place.
Chemical Plant Zone
The first Act of Chemical Plant Zone will be considerably more open in terms of which directions you can head in, which you'll notice very shortly into the level. There are only two notable hazards to be aware of here: the first is a type of enemy, which looks like a spider; if you're picked up by it, start mashing buttons quickly to release yourself from its grasp, as it'll soon self-destruct after grabbing you. Later into the level, you should come across a pink liquid that floods the area. This substance, known as Mega Mack, lacks any sort of air supply below, so you'll want to rise out of this stuff quickly. Aside from not having any air bubbles at the bottom of where it's being held in, there aren't any other effects that Mega Mack will have on you.
The boss of Act 1 will be a sort of chemical-mixing device; it will use a stomping attack like the first boss of Green Hill Zone did, and will be invulnerable until the blue chemical surrounding it turns into circular balls. Hitting the machine a few times will destroy it, making for an easy fight.
At the start of Act 2, you'll be introduced to two new features of the Zone. Jumping on a syringe with a cyan liquid in it will transform the chemicals below into cyan jelly, propelling you upwards at around the same height a yellow spring would. Green liquid from a syringe will transform cyan jelly into green jelly, and will launch you as high or higher than a red spring usually does. There are also a few more mechanics you haven't come across in Act 1, but these are rather self-explanatory.
After making your way through Act 2, you'll be shot into a small room with Eggman in a pod similar to yours. Some may recognize what's about to go down: a game of Dr. Robotnik's Mean Bean Machine. If you're not familiar with this very old SEGA title, it works fairly similar to Tetris-like games. You have to make combinations of the same color with at least four of the same-colored bean to make a black bean appear on Eggman's board. Black beans require a combo to be created adjacent to them in order to be destroyed, making things more of a hassle. You win the game by making your opponent unable to perform any more moves by filling up his board, so making multiple combos in a single move and other complicated strategies will create many more black beans at once, speeding up your victory.
From now on, descriptions of each Zone will mostly only contain boss battle information unless there's something in the Zone that proves troublesome. There aren't too many of these, so you should be able to get through most (if not all) of the rest of the game easily.
If you've passed at least ten checkpoints by now, you should get the following trophy for doing so. If you haven't gotten it yet, you'll easily get it soon enough as you play the game. At the moment, it's unclear whether or not you have to pass ten checkpoints, like the trophy says, or pass through one at a high enough speed, like the trophy's solution suggests. Either way, getting this trophy should happen naturally and unintentionally, no matter what the prerequisites are.
Studiopolis Zone
This next Zone, entirely new and not from any previous game, will be even more sprawling than the previous one. A general sense of direction will allow you to run through the first Act with ease. Some new gimmicks will be present here to give the Zone it's unique characteristics, and none of them should be too confusing. At the end of this half of Studiopolis Zone, you'll come across the Heavy Gunner, one of the five robots now evolved thanks to the power of the Phantom Ruby. The Gunner will be riding in a chopper off in the distance, and will occasionally fire missiles at you in groups. Red, generally a color to stay away from in video games, will be the color of some missiles that he fires in your direction. Red missiles, as you may have guessed, will inflict damage on you even if you hit them yourself; blue missiles, however, will be launched back at the Heavy Gunner if you hit them. Continue hitting the blue missiles back at the chopper until it's destroyed and the first of the Hard-Boiled Heavies are incapacitated.
After finding your way to the end of Act 2, Eggman will appear once again after starting up a weather machine. This machine has three different scenarios that it will create. Sometimes it'll turn up the heat, where you'll have to hide under Eggman's carrier for cover, or strong winds and thunder will toss you around the stage. In practically every second of this fight, Eggman's carrier is flying just low enough to the floor where you'll be able to hit it from ground level. Hitting him immediately as much as you can when the battle starts will make this one of the fastest fights in the entire game. In fact, I never saw any attack other than the one that creates harsh sunlight due to hitting him constantly during the battle.
After being defeated once more, Eggman will retreat to one of his most notorious creations, the Flying Battery. Sonic & Tails will rush towards it before it ascends too high from the ground.
Flying Battery Zone
The first boss of the flying fortress will be an electromagnetic device that creates enemies out of garbage; to defeat this thing, you'll have to attack the trash enemy and use it to bounce up towards the machine that created it. Another thing you could do, if you come into this fight with a Thunder Shield on you, is just use the shield's double-jump capabilities to reach the machine without having to deal with the smaller enemies it creates. Be quick about this fight, as the walls of the trash pit will slowly come in on you as time progresses.
The second boss will once again be against Eggman, this time in a spider mech. As you and Eggman ascend, rotating poles and spikes will appear on the walls to the left and right. To destroy this spider mech, you'll have to launch yourself into the mech's giant bumper and push it into the spikes on the opposite side of the room. Continuously hitting the bumper through the use of normal attacks will prevent Eggman from getting back up and using an attack of his own, albeit a very easy-to-dodge attack. This fight is very frustrating for many people, especially since it relies on the mechanics of the spinning poles, not to mention the fact that you need to hit Eggman a total of eight times to win the fight. This might be one of the very few times that you learn about the game's natural time limit; after ten minutes in a stage, you'll automatically die. Therefore, if you get to this boss at a fairly late time, you may as well restart the Act if you don't think you can beat it quick enough.
Press Garden Zone
This Zone, part Japanese garden and part propaganda factory, is another of the four new Zones to be included in the game. Progressing through the first Act, the interior of the propaganda factory, should be pretty easy to do, but the music might make you want to stay in this Act a little bit longer. The boss of this Act is another machine named the Shiver Saw. To defeat it, try to lure it into one of the orange and green boxes lying around. If the Shiver Saw hits one of these, the blade it used to do so will break, giving you a chance to strike. Six hits will take this machine down.
At the end of the Zone in its entirety, the Heavy Shinobi will appear in the garden in an attempt to ambush you. To stun him, all you have to do is jump towards him while he himself is jumping; attack him when he's stunned to deal damage until he's defeated. The Shinobi will occasionally use it's blade to attack you, which fortunately only freezes you in the same way you've likely been frozen in Act 2. Mash buttons to escape the ice and continue the fight. Watch out for the little projectiles that he throws as ninja stars, though.
After defeating the Heavy Shinobi, Sonic and Tails will come across Eggman, who has located Metal Sonic inside Little Planet, from Sonic the Hedgehog CD. It appears he's planning to invade the planet, although the convoluted events of Sonic CD make it hard to determine whether he's already done so in the past. This might even be the one time he does it, starting the events of the aforementioned game with Sonic in a different point in time. With all of this confusing time-travel talk aside, Eggman will use the Phantom Ruby to send you to Stardust Speedway, which has now been given the title of being its own Zone.
Stardust Speedway Zone
If this is your first time on Little Planet, You might find that the level design is a lot different compared to the other stages you've been in so far. This stage actually takes place in the past, so the Phantom Ruby must have sent you back in time as well. Tons of plants and orchestral equipment form this place, making for a strange combination. The boss of this Act is an enemy in massive size compared to its regular form. This giant firefly, a Hotaru, will send normal-sized ones to attack you first. The single Hotaru will be invulnerable until it stops moving and is charging up an attack. Hit it then to make a pair of Hotaru appear, which will be charging energy between the two of them. All you have to do here is jump up to one of them to destroy the chain and send the other one fleeing. This will reveal the giant Hotaru that you need to defeat. Dodge its attacks and strike back whenever possible; unlike regular Hotaru, it will be vulnerable to attack all of the time.
After the Hotaru are down for good, Sonic and Tails will use one of the signposts scattered throughout Little Planet to travel to the future; due to having been in the past, this will actually be the present. Now that you're seeing Stardust Speedway for what it should be, you'll notice that plant life has been completely removed as more brass and other musical equipment has taken over the area. After rushing through the stage to reach the end, Metal Sonic will appear and chase you until you get to a large room. Once Metal Sonic takes control of the machinery here, a small opening will periodically release yet another mechanical version of Sonic that only some will be familiar with: Silver Sonic. This mech was a boss of its own in the 8-Bit version of Sonic the Hedgehog 2 on the Game Gear and Master System, but is now a mere one-hit-death enemy. To knock Metal Sonic out of his cockpit, you'll have to use a spin dash on the Silver Sonics that appear while they also perform spin dashes; this will (hopefully) send your shiny clones into Metal Sonic, eventually forcing him out.
After Metal Sonic chases you further through Stardust Speedway Zone, he'll stop and do his signature taunt towards you, then summon a giant spike wall to chase you. In this phase of the fight, you'll finally be able to directly hit Metal Sonic. A throwback to players who have gotten to his fight in Sonic CD, you'll have to maintain your speed and hit Metal Sonic after he's done attacking you. After enough hits, Metal Sonic will be defeated and you'll leave Little Planet to find Eggman in the next Zone.
Hydrocity Zone
Hydrocity Zone, as you would have guessed, is this game's "water level". Unlike most of the other Zones so far, you won't be able to bounce around all that fast here, as one challenge of being underwater is that you need to breathe. Small air pockets are scattered around the underwater areas of the levels, and occasionally create large air bubbles that you can use to restore your breath. After making it all the way through the first Act, you'll actually hijack Eggman's cruiser and use its fan to suck the doctor into the rotating blades. As cruel as that sounds, you'll have to do this only four times to make Eggman's gear break.
For the second boss battle, Eggman will be using a small submarine to propel you to the right in a long repeating tunnel filled with water. In this state, you'll have to avoid spikes sticking out from blocks and touch circular bombs. The bombs won't explode, but will instead be activated. Since Eggman follows your position vertically in this tunnel, you'll have to make sure he stays on the same level the bomb is on so that he gets hit by it. Performing a successful attack is also the only way to create an air bubble down here, so be sure to grab it once it appears so you can stay alive for this fight. After destroying the submarine, you'll end up in a room where Eggman will use a whirlpool machine to stir things up in this partially submerged chamber. Hit him when the spinning chunks of machinery aren't spinning so fast; after this happens, he'll scrape the bottom of the room from both the left and right, so jump up and get some air while also dodging these attacks. Eggman will also use the column in the middle of the room to spin the water around; this won't damage you, but you won't be able to escape from it. The only way this attack is a threat is if you're running short on breath. Once you defeat Eggman here, Sonic and Tails will head to the desert in search of their foes and the Phantom Ruby.
Mirage Saloon Zone
The first Act of this Zone, if you're playing as Sonic, Tails, or both of them, will just be an airplane chase. At one point in the chase, you will land on Eggman's train for a brief moment; getting to the checkpoint is your biggest priority here, because it'd be a big hassle to go through the first part of this Act again. Knuckles' first stage of Mirage Saloon Zone will be completely different, and will act out like a normal level. The first boss will be one of Heavy Magician's pets, a giant Bead Worm from Sonic Chaos. As Sonic or Tails, you'll have to time your jumps to hit the underside of the head of this beast several times as it jumps overhead. If you're playing as Knuckles, the Bead Worm will toss parts of its body at you; dodge these and aim for the head.
The second Act of this Zone should be the same for all three characters. The Heavy Magician will be waiting to test some spells out once you reach it's boss fight. The Magician will transform to three characters from Sonic the Fighters: Fang the Sniper, Bean the Dynamite, and Bark the Polar Bear all make an appearance in that order as it transforms into them. Fang uses a cork popgun to attack, which might be the hardest attack to avoid. Bean tosses bombs, as you probably could have guessed, and Bark will use his strength to shake the stage and make things fall from above. Stop the Heavy Magician's illusions by merely hitting it with an attack, then hit it again to inflict damage. After eight hits, the Magician will escape after having been defeated by someone with a bit more fighting prowess.
Oil Ocean Zone
Oil Ocean's second Act boss has already become notorious for being pretty unfair. Before you get to it, you'll first have to beat the Act 1 boss. A standard repairman robot will be working on the area when you come in to stop whatever he was up to. This fight is super easy; just like Studiopolis Zone (Act 2), you can jump up and hit this mechanic at any time when he's not in the background of the stage. When he turns his wrench as he's hiding in the background, stay in the middle of the stage so you don't get crushed between the valves below and the spikes above.
Then the most annoying boss, an octopus submarine, will really try your patience. You need to land eight hits on Eggman's newest contraption, but this is going to be very hard to pull off, especially since your rings will almost always be impossible to recollect after you get hit once. One tentacle will fire lasers towards you; you can duck over the high ones, but make sure to jump over any of the others. Lasers shot at ground level will cause laser-y ripples to appear on the platforms at that level, so watch out for them when this happens. After this, two tentacles with metal balls will appear as other tentacles drag platforms into the ocean. Attacking the metal balls won't directly count towards the required eight, so hitting them is up to you; it will benefit you in the long run, so you may as well hit them before the cockpit of the submarine shows up. This fight may take you a few tries, so don't expect to get it down on the first try.
Lava Reef Zone
The first Act of Lava Reef Zone is responsible for the "Lava" part of the name; rocky caverns and lava plumes are abundant in this underground cave system, and many exploding rock-like enemies are here as well. The boss here is a giant drilling machine, which you may have seen a smaller version of in the level. It will drop down from above to attack you, but the targeting system is visible even to you, so you can dodge these attacks fairly quickly. Make it dig into the sets of rocks in the ground to make it take damage, also revealing a wooden bridge underneath the rubble. Making it dig there won't make it take damage anymore; crouch and wait for the driller to land above you, then jump to hit it when it jumps. After this, immediately curl into a ball so your head doesn't hit the main piece of the machine.
Now you get to see the reef, which will have considerably less hazards in it than the first Act had. Sonic & Tails will fight the Heavy Rider, who uses a classic Green Hill Zone enemy as a motorcycle. The Rider will zoom around the stage with a mace, and is actually (in my experience) very easy to hit. Hitting the bike enemy will just result in you bouncing back, as if you hit a bumper. The Heavy Rider will also use the ramps in the area to jump around; you might want to play it safe and not attack when this happens, because the two of them will be rushing around at very high speeds. Time your attacks accordingly, and you should have no problem taking the Heavy Rider down.
If you're playing as Knuckles, you'll face the Heavy King, who will be trying to steal the Master Emerald as the Heavy Rider distracts the other two heroes. Unfortunately for him, Knuckles is a natural protector of the Master Emerald. After remembering what happened to him the last time he tried to protect the Master Emerald, he'll get angry at the King and demand he put the giant gem down. Fighting the Heavy King is surprisingly easy. Don't get close to him when he electrifies himself, and stay off the ground when he creates a beam across the floor. His third attack creates a group of balls of electricity around him that act as shield, but he'll also use them as projectiles. Dodge these at all costs and hit him when his cover is gone. Since the Heavy King spends most of his time vulnerable and jumping around the stage, landing eight hits on him shouldn't take too long at all.
Metallic Madness Zone
This stage marks the return of the trio to Little Planet in search of Eggman. Tons of sawblades and other metallic hazards will be in your way through this Zone. Eggman will be at the end of the first Act in a contraption/room just like the Final Zone in Sonic the Hedgehog. Pistons will rumble and then crunch down on the opposing end of the room, and energy balls will slowly descend between the pistons' movements. Eggman will always be in one of these pistons, so hitting him requires fast reflexes and a bit of luck. After hitting Eggman enough times, the pistons will start to move erratically; fortunately the energy machine will have been destroyed before this phase of the battle starts, but you'll have to be even quicker on your feet to dodge the constantly-moving set of pistons. Eggman will now only appear on occasion, so you'll have to act fast when you see him.
The second boss battle is also against Eggman, but this time, he's in a machine similar to some toy machines you'd see in arcades. Since you're just about the same size as them, it should be a fair fight. Jump up and rotate the handle to release a miniature mech that can usually only withstand about three hits; they should be quite familiar to you if you've already played the original games. Amy bots will join the small mini-machines, and will try to hug you before they explode. Performing a spin dash on them will prevent them from hugging you, as well as destroy them. There are a total of eight toys for you to defeat. You can pop one open and fight them one at a time, or you could go crazy and let out as many as you can. After all eight are released, Eggman will fly away until all of the toys are defeated. When he comes back, small pellets (that inflict damage) will rain down from his machine. Dodge them and flip the handle one more time to release Eggman himself, who will escape to his new Zone that he built on Little Planet.
Titanic Monarch Zone
This final Zone generally takes a lot more time to get through when you're doing it for your first time. A new piece of this stage that takes some getting used to are plasma balls, which fling you in a direction depending on your angle and when you decide to jump from it. You can rotate your angle around these plasma balls by moving left or right. At the end of this Act is a dastardly computer boss from Sonic & Knuckles, who is perhaps just as frustrating as it was in it's original game if you don't know what to do. The spheres guarding the main component, its red eye, will eventually drop down to the floor before making the circle expand in an attempt to hit you. Avoid the spheres and hit the eye, which will destroy one sphere per hit. Once all eight orbs are destroyed, the eye will detach from the main computer and fly around the arena. Watch the signs on the elevator to determine which way it's moving, because this determines where the boss will land. If it becomes lodged in the ceiling, simply stand underneath it to avoid its attacks. If it's on the floor, run a safe distance away from it, or try to hit it while it's vulnerable. The way you're supposed to hit this thing is by jumping up to where it'll be just before the elevator takes off again, since you won't be able to jump to it when it's moving. After a few more hits in the second phase of the fight, the computer will be destroyed and the elevator will take you to Act 2.
Act 2 isn't too much of a step up from Act 1 gimmick-wise, but the level has been separated into four different areas that you need to get to the end of. Glowing areas of purple light will teleport you to various parts of the Act, and after having traversed one of the four paths, its door will close in the "hub" area. Finishing all four sections of this level will create a portal to the last standard boss of the game, which is naturally a fight against Eggman. His final machine is tied to the four corners of the room, and he uses them to electrocute you if you touch them. At first, he'll shield himself until he needs to use the machine's power to spark the four tethers. After the electricity wears off, spin dash into him or run up to him and attack. After a standard attack, he'll launch a few missiles towards you before trying to shock you again. The third of three looping attacks will consist of him using hands created by the Phantom Ruby to temporarily transport you to a room where one of the Hard-Boiled Heavies are residing. Just try to stay alive when this happens, as the Heavies cannot be defeated in this battle. It takes four hits to destroy one of the electric arms, and doing so will give yourself a little more breathing room. The lower left arm will break first, so you should hide there and hit him as soon as you can (since the arm won't be in the way anymore). After 16 total hits, the Titanic Monarch Zone will start to self-destruct; run out of there as fast as you can and escape.
If you managed to collect all seven Chaos Emeralds, you'll instead be sent to the true final Zone of the game. Since it's highly unlikely that you were able to on your first time through the game, you're still able to access the final fight of the story by replaying an easy level (generally Green Hill Zone Act 1) with the same save file to collect the rest of the emeralds. Once you have all seven, replay the Titanic Monarch Zone from Act 1 and defeat Eggman again to reach the Egg Reverie Zone. If you don't want to be spoiled, avoid the next section until you've gotten there. More information on the Chaos Emeralds is on the next page in the walkthrough.
Egg Reverie Zone
After Eggman and the Phantom Ruby teleport you to a barren place, he and the newly-upgraded Heavy King, the Phantom King, will be fighting over the Phantom Ruby. Since either of them as the owner is a good outcome, you will use the Chaos Emeralds to transform into Super Sonic, Super Tails, or Super Knuckles, but even this form is still vulnerable to attacks by both Eggman and the Heavy King. Time has been distorted here, if you couldn't tell by the clock, so you won't have to worry about a time limit. Eggman and the King will exchange possession of the Ruby as they fight both you and themselves, and both bosses will require the same amount of hits to be defeated.
As Super Sonic, you'll have to collect rings flying around in space in order to maintain your Super form. If you run out, you'll lose a life. Getting hit now only reduces your rings by a certain amount (since losing all of them would mean instant death) and using a super-fast dash in midair (double-tap a jump button) will also deplete your ring count. Fortunately, Eggman's Egg Reverie machine is very easy to avoid, so you can use the time you have against him to collect rings if you're low. Just run into the Egg Reverie whenever it conveniences you; you'll find that it's very easy to pull off. If you take too long, though, Eggman will use the Phantom Ruby to warp space around him as he dashes around the stage before returning to normal. After hitting Eggman once, the Heavy King will take his place, and will be a lot more volatile with his attacks. If you're familiar with the fight against him as Knuckles, he'll summon several balls of electricity to be used as projectiles. The Phantom Ruby's power makes these hazards a threat to you, so watch out for them and wait for an opening so you can hit the King. You can also hit the balls around him before he throws them at you, but this may or may not be a good idea, since you'd then be at very close range and you'll be very easy to hit. If you have enough rings, you can also use the invincibility frames you have after getting hit to attack the King by bypassing his projectiles and hitting him directly. If you go through with this strategy, just make sure you collect a bunch of rings when Eggman reappears.
After finally landing enough hits on both maniacs, the Chaos Emeralds will react to the Phantom Ruby and suck Sonic (canonically) into a portal along with the Ruby. The Titanic Monarch will explode just as usual, but Knuckles and Tails will now be able to watch Little Planet's chain break as it returns to its orbit around Earth. They don't know where Sonic is, but he's surely off to start another adventure.