Here is the full list of all 27 The Slater achievements.
Complete level 6 as Master
Complete level 5 as Master
Complete level 4 as Master
Complete level 3 as Master
Kill a rat
Complete the game
Complete level 2 as Master
Shoot a rat
Complete level 1 as Master
Complete level 5
Trigger police station upstairs alarm
Chat with street bum
Dress as lab worker
Get party invitation without a kill
Complete level 4
Enter a secret observation room
Sabotage ventilation system
Trigger a car alarm
Shoot a bird
Complete level 3
Shut down a metal detector
Complete level 2
Poison a drink
Sabotage all security cameras in a level
Start a lawn mower
Complete level 1
Kill a junkie