Here is the full list of all 21 GARAGE: Bad Trip achievements.
Complete the Arena Challenge
Complete the Axe-man Challenge
Complete the Skirmish Challenge
Beat the game
Kill Demikhovsky
Complete the Labyrinth Challenge
Find all the parts of Demikhovsky's diary
Pick up soap in the shower room
Kill Dreadnought
Watch a TV show
Ride the train
Unlock a combination lock
Find a condom
Dispose of the old boss
Kill the centipede
Open the shelf in the desk
Score a goal with your head
Smash 15 vending machines
Take "heavenly" pills
Kill your first cadaver
Find a secret passage