Here is the full list of all 15 VolChaos achievements.
Die by landing on some spikes.
Collect all gems in a level.
Complete a level without dying.
Finish a level in under 7 seconds.
Die 10 times on 1 level.
Get killed by a fire bat.
Die 100 times.
Die 100 times in lava.
Get the flag after lava has reached it.
Finish level 49 in under 49 seconds.
Collect all gems in 10 levels.
Complete an expert level.
Finish all normal levels.
Finish all expert levels.
Find the mythical Fun Sloth.