This trophy requires that you get all 14 weapons upgraded. (The Hologuise does not count, being as it is neither a weapon nor can be upgraded.)
This will require a second challenge playthrough. (Weapons can only be upgraded to level 5 in a first playthrough, you'll need to upgrade them to level 10 [through unlocking their cardset that is only available through the challenge playthrough]).
Here are a list of the weapons required (keep in mind that their names change to this as they are upgraded):
Fusion Bomb, Magmabuster, Lavacitor, Protoclast, Groovibomb, Pixelizer HD, Zurkon Jr., Peacemaker, Plasma Slayer, Doom Blades, Apocalypse Gloves, Goatinator, RYNO Xtreme!!!* and Raptor Launcher**.
* The RYNO Xtreme!!! is unlocked after you acquire it by going to the RYNO dealer after completing the RYNO set.
** Raptor Launcher can be missed. It is found during an optional mission found on Nebula G34.
Make sure you keep on top of upgrading their effectiveness using raritatinum crystals.
Your weapons' leveling speed is determined by the difficulty of the enemy you use it on. Therefore, it is within your better interest to try to spend time leveling them up on some of the more later levels.
Keep in mind that the Groovitron/Groovibomb is a fantastic tool in leveling up some of the more difficult weapons. Toss one of those puppies in the rink and as your enemies are dancing, use the opportunity to shoot your lower level weapons at them.
Now, here's the strategy I used: VVVVVVVVV
After collecting all of the gold bolts, go to "cheats" in the "extras" menu, and turn on invincibility. Do not turn on infinite ammo, as your weapons will not upgrade if you do. I also turned on "fast" game speed to speed things along.
On the final boss (after busting through the grindrailing sequence), fly around as needed and just unload all of your weapons on the boss*. Also, it isn't a bad idea to take him down to about 75% so he breaks the first platform. After he does, more baddies will spawn that you can use to seed your leveling.
* With the exception of the Sheepinator/Goatinator. It will not work on the boss. Also, the RYNO tends to be slightly OP, so make sure if you use that, you keep in mind that the boss's health will quickly vanish.
Keep an eye on your jetpack fuel. While your health may be unlimited, your fuel is not.
Fly around the platforms, and play the boss as you normally would. When the boss's health gets low, or you aren't able to get ammo for your weapons fast enough, fall to die. The boss fight will start over, but you will have your weapon ammo restocked and weapon levels saved.
For the Goatinator, I just flew from platform to platform killing the robots and ignoring the boss. When they didn't respawn fast enough, I died.
If you need to upgrade your weapons to the next tier, need to step out to collect raritanium/bolts/cards, or simply need to use the gadgetron vendor, finish killing the boss. Speed through the credits, and hit "continue" instead of starting a "challenge playthrough". Your game will restart with you outside the boss-loop, so you can use the vendor, go collect more stuff, or jump back into the boss battle.
Have fun!