Here is the full list of all 7 Boris the Sloth achievements.
Defeat the bear that is guarding Euka.
Take revenge on the evil mandrake that kidnapped Euka.
Collect all of the sleeping frogs that are used for the time warp ability.
While in the spirit realm, hop out of and back into the anti-gravity portal without touching the ground (or vice versa).
Dash killed 3 or more enemies at one time.
Die 100 times.
Find the secret level.