Here is the full list of all 18 The Excrawlers achievements.
Complete the tutorial
Find Tarik's Gunpowder
hit all the targets in the level
Find the Lesovick
win 10 arenas
Use 5 skill points
Collect 20 gems
Perform a combo of 20+ hits without taking damage
Reach Level 10
Defeat Maduk
Find the secret place in the forest
Find Holeyd
Improve the gem
Burn the web
Find the Gribster
Burn the ogre camp
Find a Restorer
Find T-1 & S-2