Here is the full list of all 33 Boo Bunny Plague achievements.
You collected all of the coins in the credits
Beat the game on Impossible mode!
Collected All Audio Lore in one game.
Collected the Frankenstrat.
Stun Thor 10 times with his own hammer.
Hit the giant donut!
Burn enemies 50 times.
Bounced on vikings 50 times
Destroyed all of the Bunny's in the factory
Watched the entire after credits scene
Defeated the Chairman
Unlocked Impossible mode!
Defeated the Secretary
Defeated Heimdall
has defeated Thor, Garmr, Hel ,Tyr and Heimdall
Somehow managed to fall through the world and hit a kill zone
Defeated all Four Horsemen of the Apocalypse
Defeated Death
Defeated Famine
Defeated War
Defeated Pestilence
Collected the Electric guitar.
Defeated Tyr
Defeated Hel
Collected the Ice guitar.
Defeated Garmr
Triggered Faye's transformation
Defeated Thor
Collected the Fire guitar.
Used Gunny to defeat an enemy.
Collected the Streetz guitar.
Collected the "Useless" Acoustic
Defeated TRex