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