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