| Achievement | How to unlock | Points
|
|---|
| Able Underwearrior | Survive 5 minutes in Endless Butt-em-up | 50
|
| Apprentice Underwearrior | Survive 2 minutes in Endless Butt-em-up | 25
|
| Battle Tested | Play either Classic Battle - Free For All or Team 30 times | 20
|
| BOGUS (secret) | Discover BOGUS | 10
|
| Butt-em-up Battles Act 1 - Gold | Achieve gold for all levels of Butt-em-up Battles Act 1 | 40
|
| Butt-em-up Battles Act 1 - Silver | Achieve silver for all levels of Butt-em-up Battles Act 1 | 30
|
| Butt-em-up Battles Act 2 - Gold | Achieve gold for all levels of Butt-em-up Battles Act 2 | 40
|
| Butt-em-up Battles Act 2 - Silver | Achieve silver for all levels of Butt-em-up Battles Act 2 | 30
|
| Golden Achiever | Play either Hold the Gold - Classic or Bare Buns 30 times | 20
|
| KO | Play either Knockout - Classic or High Health 30 times | 20
|
| Patient Player (secret) | Wait 15 minutes in the "Choose Your Underwearrior" screen | 15
|
| Thank You! (secret) | Watch the credits till the end | 10
|
| The Basics | Complete all of "The Basics" lessons | 10
|
| Tighty Whitey Targets Master - Gold | Achieve gold for all levels of Tighty Whitey Targets Master | 40
|
| Tighty Whitey Targets Master - Silver | Achieve silver for all levels of Tighty Whitey Targets Master | 30
|
| Tighty Whitey Targets Pro - Gold | Achieve gold for all levels of Tighty Whitey Targets Pro | 40
|
| Tighty Whitey Targets Pro - Silver | Achieve silver for all levels of Tighty Whitey Targets Pro | 30
|
| Tighty Whitey Targets Skilled - Gold | Achieve gold for all levels of Tighty Whitey Targets Skilled | 40
|
| Tighty Whitey Targets Skilled - Silver | Achieve silver for all levels of Tighty Whitey Targets Skilled | 30
|
| Tighty Whitey Targets Trainee - Gold | Achieve gold for all levels of Tighty Whitey Targets Trainee | 40
|
| Tighty Whitey Targets Trainee - Silver | Achieve silver for all levels of Tighty Whitey Targets Trainee | 30
|
| Ultimate Underwearrior | Survive 10 minutes in Endless Butt-em-up | 100
|
| Underpants Collector Master - Gold | Achieve gold for all levels of Underpants Collector Master | 40
|
| Underpants Collector Master - Silver | Achieve silver for all levels of Underpants Collector Master | 30
|
| Underpants Collector Pro - Gold | Achieve gold for all levels of Underpants Collector Pro | 40
|
| Underpants Collector Pro - Silver | Achieve silver for all levels of Underpants Collector Pro | 30
|
| Underpants Collector Skilled - Gold | Achieve gold for all levels of Underpants Collector Skilled | 40
|
| Underpants Collector Skilled - Silver | Achieve silver for all levels of Underpants Collector Skilled | 30
|
| Underpants Collector Trainee - Gold | Achieve gold for all levels of Underpants Collector Trainee | 40
|
| Underpants Collector Trainee - Silver | Achieve silver for all levels of Underpants Collector Trainee | 30
|
| Underpants Enthusiast | Play Underpants Collector multiplayer mode 30 times | 20
|