These are the weapons required to be held/have ammo for in order for the achievement to unlock:
- Duke's Mighty Foot (always available)
- Pistol
- Shotgun
- Chaingun
- RPG
- Pipebomb
- Shrinker
- Expander
- Devastator
- Laser Tripbomb
- Freezethrower
- IncineratorAs the Incinerator is only found in
Episode 5: Alien World Order, this is the only set of levels where the achievement can be obtained without the use of the cheat menu.
I personally obtained this in
Level 4 of Episode 5:
Mirage Barrage; the level has a ton of enemies that carry ammo for just about everything. If you play through the episode from the beginning of
Level 1: High Times, you should already have most of what you need. As you progress through Mirage Barrage, you will come across rooms that contain the more uncommon weapons/ammo, such as the Freezethrower, Shrinker, and Expander. Just be sure to search every room thoroughly so you don't overlook anything! The in-level secrets shouldn't be necessary to obtain the weapons you need, either, so don't worry if you're having trouble finding them.
If you would rather not search for the weapons, and prefer to use the in-game cheat menu, enter
in succession. Select either "Give All" or "All Weapons" (Give All is preferred if you take this route anyways, since you get more to use while using less of your time re-entering the cheat menu later), and you should receive the achievement then.