Here is the full list of all 42 Bullshot achievements.
Break the car in the bonus stage
Escape from the prison
Finish a non-bonus stage without jumping
Find the reader in the prison
Finish the Oil Fields stage.
Destroy the heart of the giant worm
Finish the desert stage
Watch the credits.
All that glitters...
Find the reader in the sewers
Kill 100 cardesians
Finish a stage with full health
Kill 10 cardesians
Change the settings of the TV filter.
Find the collectables in the prison
Free all B.O.A. in the prison
Finish the sewers stage
Find the collectables in the sewers
Kill 1000 cardesians
Find the collectables in the desert
Destroy the van from above
Finish the biker stage
Find the reader in the desert
Finish the heart in the bloodiest way
Charge 100 enemies in one game.
Finish the bio technology lab stage.
Find the collectables in the bio technology lab.
Find the collectables in the oil fields.