Here is the full list of all 16 Jelly Killer achievements.
To destroy 16 hazards holding control over a guardian
To complete the game
To get into a wrong place
To use a teleporter 8 times
To destroy a body 32 times being close to the exit
To be impaled 32 times holding human body under control
Kill a human with a rifle
To die 32 times
To complete training
To take in all the five characters’ bodies
To enter a pipe holding control of a human being
To get 8 headshots from turrets
The quickest way to become a general
An attempt to take control over a non-organic creature
To escape a human body for the first time
To die 4 times at the same place