Here is the full list of all 15 VolChaos achievements.
Finish all expert levels.
Finish all normal levels.
Finish level 49 in under 49 seconds.
Find the mythical Fun Sloth.
Die 100 times in lava.
Die 100 times.
Complete an expert level.
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.