Here is the full list of all 22 No More Heroes 2: Desperate Struggle achievements.
Defeated Skelter Helter.
Defeated Nathan Copeland.
Defeated Charlie MacDonald.
Defeated Matt Helms.
Defeated Cloe Walsh.
Defeated Dr. Letz Shake.
Defeated Ryuji.
Defeated Margaret Moonlight.
Defeated Captain Vladimir.
Defeated Alice Twilight.
Defeated Jasper Batt Jr.
Defeated Mimmy in Henry's dream.
Defeated Kimmy Howell.
Finished all training exercises at Ryan's Gym.
Defeated all Death Match opponents at least once.
Played all eight side jobs at least once.
Completed Jeane's training and learned Step-n-Slice.
Used whatever means available to beat 510 regular enemies.
You have used every single toilet in the game. Amazing, and a bit worrisome.
You have achieved all the achievements!
You defeated Million Gunman.
You defeated New Destroyman.