South Park Tenormans Revenge

There are five different weapons in the game. They are:
Baseball bat, crowbar, bubble gun, water bombs and "vortex gun"

Here are examples on where to find the different weapons:
Baseball bat, crowbar and bubble gun can all be found on the first level, South Park 2546.
Water bombs can be found on the level Pi Pi's Splashtown.
“Vortex gun” can be found on the level Park County Dump, during the Tenorman fight.

Use them all on an enemy to unlock the achievement.