This will be an alphabetized list of all the items in the game. Some are very useful and wonderful, some are utter rubbish and should never even be glanced upon. You need to pick up every item at least once, so make sure to finish your run once you acquire a new item for the first time. Most items need to be unlocked by meeting unlock criteria, so I will list the unlock in parentheses next to the item name. After acquiring that unlock, the items will be able to be found in the game. I suggest copying this guide over into a text editor of some sort and deleting entries as you pick them up to avoid confusion.
Aadaru's Swordfish - Dropped by Aadaru, gives you a slower version of the spinning swordfish he uses. Incredibly useful, as it spins around you and can hurt any enemy in your immediate vicinity. Best used if doubled with Blast Shield, as the swordfish can destroy barrels that you're near and damage you with the explosion.
Adderall (Unlocked with Addicted) - This little circular pill gives you a speed increase, so it is always recommended you pick it up. Only $100 in the shop.
Angel Wings (Unlocked with Bottom Feeder) - One of the best items in the game, these wings allow you to double jump, making you a harder target to hit and a more maneuverable character. If you pick up Iris' Wings in the same run, you will have infinite jumps, a combination that allows you to destroy most bosses without a scratch. $325 in the shop.
Anchor - Lets you fall faster. No huge benefit or detriment, only $50 in the shop. Only bother if you haven't gotten it yet or are on your OP run.
Armor Box - Works as advertised, gives you some shields. It's a single time use, good in case you're in a jam and need some padding. $150 in the shop.
Banshee's Scream - Dropped by the Banshee, gives you a solid damage increase. Certainly worth picking up no matter what.
Beard (Unlocked with Gorton) - The item that makes the sickle incredibly overpowered, the Beard will exponentially increase your damage the closer you are to an enemy. Absolutely destroys bosses such as Aadaru and Dahlia later in the game. $300 in the shop.
Blast Shield - Another amazing item, this makes you immune to all explosive damage. Meaning that your own bombs, grenade launcher, exploding enemies, barrels, and turtle rockets no longer damage you. Very useful for all characters, but absolutely necessary for Dy-No-Mite. $150 in the shop or can be found by destroying an explosive barrel at random.
Bloody Doubloon (Unlocked with Frugal) - Items in the shop cost health instead of money. If you have tons of health to spare or have a floor with numerous health pickups waiting for you, might be worth the investment. $200 in the shop.
Blowfish - Dropped by the Angler fish or can be acquired from the shop for $350. I love this item as it does poison damage on top of your weapon damage, really destroying enemies and bosses incredibly quickly. Always pick this up.
Bomb Box (Unlocked with Hehehe) - Gives you a number of bombs. Great for Kamikaze or if you have other powerful bomb items. Only $50 in the shop.
Bottle Opener - Removes limitations of Superweapon ammo. Let's you have as much ammo as you want in your secondary weapon. Never a negative item to have. $300 in the shop.
Bucket of Tar - Puts your Superweapon ammo to 100. If you're in need, take it. Not a permanent item. $100 in the shop.
Can of Beans - One of the better items, inflicts poison damage to any nearby enemies. Works wonders against Skorchers and monkeys, as they enjoy getting in close and doing contact damage to you. $300 in the shop.
Cannonball (Unlocked with Pacifist) - Increases damage but decreases fire rate. Good for weapons such as the sickle and Gilead Gun, not the best with the shotgun or grenade launcher. $275 in the shop.
Chain (Unlocked with Serious Player) - Heavily increases your fire rate. Perfect for the shotgun and sickle, but definitely a keeper on any weapon. A hefty $1000 in the shop.
Chainsaw - Every bomb that detonates turns into a chainsaw that rises up from the ground. Really damaging when paired with Powder Keg and Cherry Bomb, but use at your own risk. $200 in the shop.
Cherry Bomb (Unlocked with Dynomite) - Breaks your bombs up into 3 or 4 cluster bombs to deal more damage. Perfect if using Dy-No-Mite or just have Blast Shield and lots of spare bombs. $400 in the shop.
Chosen One (Unlocked with Chosen One) - Allegedly, double tapping in any direction let's you do a quick dash in that direction. It has never worked properly for me, and instead throws me into enemies and through doors I was trying to survey. Only use it for OP and when you need it the first time, otherwise leave it alone. $230 in the shop.
Coin 'o Fate - A tricky one. The coin will flip after you pick it up, landing on either the happy side or the skull side. Happy side grants you a decent stat upgrade in every area. Skull side results in a health decrease by 3 slots. Use at your own risk. $150 in the shop.
Compass (Unlocked with Completionist) - One of the very best items you can get. It will show you the entire floor on the mini-map, allowing you to check the route to the nearest exit before even leaving the elevator. A huge help on your speedrun, or just beating hardcore without a Dingy. $350 in the shop.
Dahlia's Knife - Dropped by Dahlia and can damage the Ghost once picked up, necessary to complete hardcore mode properly.
Davy Jones' Locker (Unlocked with Picky Eater) - Another item you want to get ASAP, this one gives you 4 health, a number of shields, and an upgrade to all stats. Hopefully you have some Scissors handy, as it costs a whopping $1250 in the shop.
Dingy - One of the most useful items by far, this will decrease the floor size down to 8 rooms. Absolutely essential for beating hardcore whilst going into every room, also quite helpful for your speedrun or regular hardcore runs. $175 in the shop.
Dobee's Blubber - A speed reducing item dropped by Dobee that I actually recommend you get. It's a permanent health increase of 6, which is just way too good to pass up on, especially playing as Gorton or Bouncer.
Doxy - Worthless. Changes the noise you make when you take damage. $0 in the shop but does count as an item towards OP.
Evil Eye - Shots will pierce enemies instead of stopping on impact with them. The sickle does this no matter what, so only good for shotguns, flak cannons, and the like. $300 in the shop.
Eye of Dobbz - Awful if you don't have Eyepatch, this turns every floor dark. If you do have Eyepatch, you can use it to farm jellyfish on every floor for money, shields, and health. Otherwise, avoid at all costs. $300 in the shop.
Eyepatch - Definitely a must have. Allows you to see on dark floors almost as if they were normal floors. You give up your crosshair in the process, but you should have no problem using intuition to aim anyway. Only $100 in the shop.
Flipper - Makes projectiles bounce around, and is rather worthless. Make sure to avoid it when using Dy-No-Mite, as your grenades won't hit the intended targets as much as you'd like them to. $450 in the shop for some reason.
Flip-Flop - Takes longer for dangerous floors such as lava and acid to damage you. Not a bad item, but is far inferior to the Hull and Hotfeet. Only $150 in the shop.
Fool - You'd have to be a fool to use this item. Doubles damage both dealt and taken, and there are far too many enemies that hit you far too often to risk this item. $350 in the shop.
Ghost (Unlocked with Who Ya Gonna Call?) - A rather useful item, holding [cn_LT] allows you to float and remain suspended. The downside is that you float rather slowly, making you an easy target for certain enemies if you're not careful. A pricey $600 in the shop.
Green's Ovaries - A pretty decent item, gives you longer moments of invincibility between hits. Great if you get backed into a corner by a monkey, for example. $350 in the shop.
Gaangus' Soul - One of the worst items in the game. Completely negates all jumping items and instead pulls you to the ceiling when you jump. Leaves you vulnerable and makes you want to vomit. Never use it, especially not for the $400 it costs in the shop.
Gum - Makes your bombs and grenades stick to the first thing they touch. Can be rather useful, only $50 in the shop.
Hanz's Coat - One of the 3 items that can be dropped by Hanz, but is by far the most useful. Gives you 2 more health slots and 5 free shields. Always worth picking this one up.
Halo - Decreases the chance of a dark floor showing up. Definitely not a bad item to have if Eyepatch is nowhere to be found, plus it's only $175 in the shop.
Heart Box - Just as advertised, gives you some health. Unless you're 4 or more health shy of your max, or if you have Iron Heart, not really worth the investment. $100 in the shop.
Holy Water - Restores you to whatever your max health is. Could help you out of a jam. $150 in the shop.
Hook - Gives you a small damage boost, always worth taking when you find it. $150 in the shop.
Horseshoe - Increases the chance that enemies will drop more shields, health, or money. Always a useful tool to have around, but $250 in the shop.
Iris' Wings - Dropped by Iris and Aeries, gives you double jump. If combined with Angel Wings, allows for unlimited jumps. One of the most useful combos in the game.
Iron Heart - Another awesome item and one of the best there is. This one removes the cap to your health, meaning you could have 6/4 health, or as much health as you can find. Get this no matter what, but it does cost a very hefty $750 in the shop.
Kamikaze - An odd one that can be very helpful or a huge hindrance. Your bombs are now your health, so any damage done to you results in a small explosion and the loss of a bomb. One run, as Dy-No-Mite, I finished with over 100 bombs. I say avoid picking this up early in the game, when you have 30 bombs or less. Snag it on the 6th or 7th floor, when you should have 50+ bombs and enjoy your huge surge of health! $150 from the shop.
Keg - Gives you an extra 3 health and completely heals you. One of the better items in the game, be sure to always pick this one up. $230 in the shop.
Kiss of Death (Unlocked with Genocidal) - Gives a large damage boost, always be sure to pick this one up when you see it. $300 from the shop.
Lead - Increases your damage but decreases your speed. The trade off is most certainly not worth it, this is one to avoid.
Left Hand (Unlocked with True Victory) - Removes your main weapon and gives you unlimited Superweapon ammo. This one is needed for the Heavy Hitter unlock, but otherwise isn't really worth the trouble. A very expensive $690 in the shop as well.
Lighthouse - A great item, grants you 3 shields when you reach 1 health. If you get another health item and are knocked down back to 1 health again, you get 3 more shields. Great to use with the Shell item. A large $720 in the shop.
Lightning Bolt - Increases fire rate and movement speed, always an item worth picking up. $400 in the shop.
Magnet - A useful little item, attracts every dropped item in the room to you besides items and power-ups. So any money, shields, or health needed in the room gets sucked up to you. Only $50 in the shop as well.
Mario - Horrible little item. Jumping while in the air brings you back down to the ground. Avoid this and only use items that increase your jumping abilities. $160 in the shop.
Mega Bullets - Not a bad item, gives you a small damage increase. Better than nothing and only $100 in the shop.
Mermaid's Harp - Dropped by the Mermaid, makes it harder for the white projectiles launched by moths, the ghost, and some bosses to track and hit you. A must-have on hardcore.
Mushroom - Shrinks you down and makes you a smaller target. Makes you harder to hit overall, but makes you completely immune to Aadaru and his spinning blades. A must have for only $250.
Mystery Box - For $200, gives you a random item. Use at your own risk!
Mystery Chest - For $500, gives you 2 mystery items. Definitely use at your own risk!
Naval Training - Increases your damage and fire rate, a very useful item that you should always make it a point to pick up. $400 in the shop.
Oar (Unlocked with Unsure Footing) - Allows you more control over your movement in the air. Not the worst thing to have for only $150.
Oil Can - Slight damage increase, so another item you should pick up just to have that little extra buff. $150 in the shop.
Omni's Tentacles - Dropped by Omni the Octopus, gives you a speed boost. Definitely worth always picking up.
Piracy - Gives you $10 every time you get hit. No hindrance to having it, but don't try to get hit regardless. $225 in the shop.
Piece of Eight - Increases damage and speed, so most certainly something you should take with anyone. $400 in the shop.
Powder Keg - Doubles your bomb damage, so a must have when using Dy-No-Mite. $150 in the shop.
Poison Bomb - In addition to regular damage, bombs will now poison enemies as well. Another huge boost if you're using Dy-No-Mite in particular. $150 in the shop.
Power of the Gods - For a mere $50, it will spawn a random power-up. You're more likely to get something useful, so worth a shot if you don't have a power-up on you at the moment.
Propeller - Increases fire rate, particularly useful for Tank and Dy-No-Mite especially. $150 in the shoppe.
Rabbit's Foot - A pretty good item, increases the frequency of power-up drops such as Ankh and Golden Scissors. $200 in the shop and worth the purchase.
Rage - Gives a very slight damage increase for each enemy killed. This one can add up, so I recommend grabbing it earlier on if anything. $300 in the shop.
Red Tearstone Ring - Activates when you only have 3 health left, and the lower your health is the more damage you do. If you're playing as Bouncer and still have 0/0 health when you get this item, you continually do double damage. $350 purchase.
Rum - Not a recommended one at all. Gives you a boost in fire rate and damage, but permanently knocks off 3 of your max health. One I always avoided. $250 to get it.
Sail - You move faster while in the air. Always a useful one to have on you, only $150.
Sandshark - Increases your speed, but only while on the ground. Still worth having on you, but it carries a $400 price tag.
Scissors - The earlier you can get this, the better. Permanently halves all prices of shop items, can also work in conjunction with the Bloody Doubloon. Cut prices again if you also use a Golden Scissors powerup while you have this one active. $350 to purchase.
Scubalien's Shell - Dropped by Scubalien, this makes your bombs bounce around as shells before exploding. An utterly useless powerup, especially bad as Dy-No-Mite, that I don't recommend ever getting it unless absolutely necessary.
Sea Legs - Triples your speed. With almost every character, the increase is way too much and induces confusion as well as extreme nausea. However, it works decently well with Tank since he is so painfully slow. With everyone else, use at your own risk. $600 in the shop.
Shell (Unlocked with Too Easy) - An odd one, you lose your hearts before your shields. To me it doesn't matter, because no matter where it comes off you're still taking damage. Could be more useful when used with the Red Tearstone Ring or Lighthouse. $400 in the shop.
Shield Lover - Enemies drop shields more frequently, I definitely suggest picking this one up. $200 in the shop.
Ship's Hull - Dropped by the Ship boss, this makes you totally immune to all lava and acid damage. Definitely worth picking up, as it evens out the playing field on otherwise disadvantageous rooms that contain floor hazards.
Skullito's Soul - Dropped by Skullito, allows your bombs to float instead of drop straight down. Useful with Dy-No-Mite as per usual.
Snail Shell - A horrible item dropped by the Snail that should never be picked up. Gives you 8 or so shields, but permanently decreases your speed. The shields will eventually deplete, but your speed won't return to normal. Avoid, avoid, avoid.
Speiga's Fangs - Dropped by Speiga, they give you a damage up and poison. If coupled with the Blowfish, bosses get absolutely destroyed by the poison damage. Worth getting.
Spinach - Gives you 2 more max health and allows you to throw the bomb and sickle further. Could be worth it, if you can get used to the new distance with the sickle easily. $250 in the shop.
Spring - Let's you jump higher. A decently helpful little item for only $150.
Starfish (Unlocked with Twice the Fun) - By far one of the best items, hands down. If you die on any floor, you will respawn on the elevator with all of your health and any cleared rooms remaining cleared. A steep $600, but it is certainly worth the extra security.
Superammo Boost - Each packet of Superweapon Ammo gives you 10 bullets instead of 5. Not a bad item, but only worth paying for if you frequently use your Superweapon. $300 in the shop.
Tesla Coil - Increases the ammo cap of your Superweapon to 200, useless if you have a Bottle Opener. This one is only $100 in the shop.
Trigger Finger - Another $100 shop item, this one slightly increases your fire rate. Not a bad one to have around.
Vampire - A strange item, this one takes health away from you every few seconds, but each enemy killed drops health. Could be used in conjunction with a Red Tearstone Ring or an Iron Heart, but I recommend to avoid it altogether. $350 in the shop.
Vitamin C - Gives you some extra health slots, always pick it up and use it. A mere $120 in the shop as well.
Winged Foot - Grants you a nice increase in speed, definitely worth picking up for the $200 price tag.
Zen Focus - $200 gives you access to longer power-ups, which is really awesome for things like Assault or Ankh during a tough fight or floor.
Collecting all of these items over time will eventually grant you:
Unlock 8/45 - Finders Keepers
I'll now discuss power-ups, which are consumable items dropped by enemies. They're not related to any unlockdirectly, but they make life one hell of a lot easier. Some are unlocked in the same way that items are. Once you collect an item and you see it in the bottom right of the screen, hit [cn_A] to use it.
Ankh (Unlocked with Good Start) - Gives you invincibility while it's active. Amazing powerup if you're in a jam or if you're going to start a hard fight and want to get in close and end it quickly, without worrying about being hurt. I always had one on me on floors 7 and 8 in case of emergency.
Assault - Doubles your fire rate and damage output, absolutely shreds boss enemies. I like to have one on me for annoying mini-bosses like the Moth and 4 legged Gilead. A nice one to keep handy.
Battery (Unlocked with Tyrus) - Refills your Superweapon ammo to 100. Useful for a Converter to soak items from it.
Dice - Re-rolls all items on the floor, which includes boss drops, shop items, and armory weapons. Note that the armory weapons could easily become items, giving you free items on the floor. I usually held a pair of these on me while exploring a floor.
Golden Heart (Unlocked with Tank) - An awesome powerup, automatically refills your health to max. Saved my life multiple times on Dahlia and Ghost fights.
Golden Scissors (Unlocked with Moneybags) - Cuts all shop prices on that floor in half. Can be paired with the Scissors item and Bloody Doubloon for maximum effect.
Hotfeet - Not very useful, this powerup negates damage from lava and acid. Just avoid that stuff anyway.
Runner (Unlocked with Gotta Go Fast) - Gives you a massive speed boost, could certainly be useful if you're a bit sluggish.
Slowmo - Slows down the in-game clock, making everything move more slowly and less hectic. Can be used for an amazing and life-saving glitch, detailed in the Hints and Tips page.
Wildcard (Unlocks with There's More?) - Gives you a random effect of any of the above powerups. Hope you're feeling lucky!
Although they're not "items", I shall include weapons below. Most are available in armories from the start, and are unlocked as starting weapons for certain characters after completing a mode with them. If you see a new one, pick it up and use it once for credit, then return it if you wish. Most are pretty awful, so don't try to use them for any reasons other than the weapon unlock.
Blowfish Gun - The Superweapon used by Gorton, this gun shoots out a homing Blowfish that does poison damage on impact. Not the best gun, but is useful against moths and monkeys as long as you don't get caught up in the splash damage.
Cannon - Tank starts with this Superweapon. It takes ages to prepare and fire, but deals a massive amount of damage. Never use it, it's awful.
Converter - My go-to Superweapon isn't even a weapon. This device converts Superweapon ammo into health, shields, bombs, or money. When used with a battery, can drop you tons of items that can save your ass before a tough floor or fight.
Crossbow - The starting main weapon of David Bowie. Terrible weapon, despite its high damage output. Needs to be fully charged to go any amount of considerable distance, like the sickle, but isn't nearly as powerful.
Flak Cannon - Bouncer starts with this terrible weapon, it just bounces around the room and barely does any damage when it touches an enemy. Avoid when possible.
Gilead's Gun - Gilead starts with this gun, shockingly, and it's not the worst one on the list. It has a weak attack but a high enough rate of fire to put pressure on enemies and bosses. Trade up for a sickle when possible, as usual.
Grenade Launcher - The 2nd best starting gun, this shoots out bombs in unlimited amounts. Best used in conjunction with Blast Shield, Powder Keg, Cherry Bomb, Chainsaw, and Poison Bomb for maximum destruction.
Hanz's Pistol - This pistol can be dropped by Hanz after killing him, or acquired as a starting weapon for David Bowie. Not a bad gun, and can help you in a pinch.
Laser Rifle (Unlocked with Gilead) - Can be unlocked for Gilead or found in an armory. Shoots out a laser that deals moderate damage, nothing to write home about.
Laser Shotgun - Takes ages to charge up and fire, awful weapon that shouldn't be used by any means.
M14 (Unlocked with OP) - This gun does decent damage, but firing it has such a horrible visual effect I felt sweaty and nauseous whenever I used it. I don't recommend trying such an item aside for the unlock, use at your own risk.
Rocket Launcher - Shoots out a rocket in a painfully slow fashion. Does decent damage, but is just way too slow to be used efficiently.
Shotgun - Tank starts with this weapon and it does a decent amount of damage. The fire rate is abysmally slow, and is pretty much useless without a Chain item to accompany it.
Sickle - The good stuff, Gorton starts with this jewel and it is very necessary in order to complete the game consistently. When thrown, it hovers in mid-air before returning to you like a boomerang. The key is to get the proper distance from an enemy so that the sickle may hover inside their body for the duration of that animation, doing continuous damage to them. Once you have the trick down, most normal enemies become a breeze. Learn how to use this weapon and use it well, it will save your life.
Tenchi's Sword - Dy-No-Mite starts with this incredibly powerful melee weapon, use this in close quarters fights that the grenade launcher won't work very well in, such as against moths.
Trident (Unlocked with Heavy Hitter) - Poseidon has a chance of dropping this weapon after you defeat him, but it's unlikely. This was the hardest weapon for me to find, and I eventually resorted to restarting games as Mystery Man until I was given it in the beginning. This item can be thrown for massive damage, but you'll need to retrieve it after the throw. If you have the Magnet item, it will return to you automatically.
Equipping and using every weapon will earn you:
Unlock 9/45 - Collector
So that's your arsenal and competitive edge, time to get into what you'll actually be fighting!