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