Here is the full list of all 15 VolChaos achievements.
Die 100 times.
Die 100 times in lava.
Die 10 times on 1 level.
Complete a level without dying.
Finish a level in under 7 seconds.
Collect all gems in a level.
Die by landing on some spikes.
Get killed by a fire bat.
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.