| Achievement | How to unlock | Points
|
|---|
| - Survive 5 minutes in Endless Butt-em-up
| |
| - Survive 2 minutes in Endless Butt-em-up
| |
| - Play either Classic Battle - Free For All or Team 30 times
| |
| | |
- Butt-em-up Battles Act 1 - Gold
| - Achieve gold for all levels of Butt-em-up Battles Act 1
| |
- Butt-em-up Battles Act 1 - Silver
| - Achieve silver for all levels of Butt-em-up Battles Act 1
| |
- Butt-em-up Battles Act 2 - Gold
| - Achieve gold for all levels of Butt-em-up Battles Act 2
| |
- Butt-em-up Battles Act 2 - Silver
| - Achieve silver for all levels of Butt-em-up Battles Act 2
| |
| - Play either Hold the Gold - Classic or Bare Buns 30 times
| |
| - Play either Knockout - Classic or High Health 30 times
| |
| - Wait 15 minutes in the "Choose Your Underwearrior" screen
| |
| - Watch the credits till the end
| |
| - Complete all of "The Basics" lessons
| |
- Tighty Whitey Targets Master - Gold
| - Achieve gold for all levels of Tighty Whitey Targets Master
| |
- Tighty Whitey Targets Master - Silver
| - Achieve silver for all levels of Tighty Whitey Targets Master
| |
- Tighty Whitey Targets Pro - Gold
| - Achieve gold for all levels of Tighty Whitey Targets Pro
| |
- Tighty Whitey Targets Pro - Silver
| - Achieve silver for all levels of Tighty Whitey Targets Pro
| |
- Tighty Whitey Targets Skilled - Gold
| - Achieve gold for all levels of Tighty Whitey Targets Skilled
| |
- Tighty Whitey Targets Skilled - Silver
| - Achieve silver for all levels of Tighty Whitey Targets Skilled
| |
- Tighty Whitey Targets Trainee - Gold
| - Achieve gold for all levels of Tighty Whitey Targets Trainee
| |
- Tighty Whitey Targets Trainee - Silver
| - Achieve silver for all levels of Tighty Whitey Targets Trainee
| |
| - Survive 10 minutes in Endless Butt-em-up
| |
- Underpants Collector Master - Gold
| - Achieve gold for all levels of Underpants Collector Master
| |
- Underpants Collector Master - Silver
| - Achieve silver for all levels of Underpants Collector Master
| |
- Underpants Collector Pro - Gold
| - Achieve gold for all levels of Underpants Collector Pro
| |
- Underpants Collector Pro - Silver
| - Achieve silver for all levels of Underpants Collector Pro
| |
- Underpants Collector Skilled - Gold
| - Achieve gold for all levels of Underpants Collector Skilled
| |
- Underpants Collector Skilled - Silver
| - Achieve silver for all levels of Underpants Collector Skilled
| |
- Underpants Collector Trainee - Gold
| - Achieve gold for all levels of Underpants Collector Trainee
| |
- Underpants Collector Trainee - Silver
| - Achieve silver for all levels of Underpants Collector Trainee
| |
| - Play Underpants Collector multiplayer mode 30 times
| |
