Here is the full list of all 7 Dwarfender achievements.
Complete Dwarfender !
Find the secret treasure chest on each level.
By using the lever on level 2, clear all waves with a different layout of the doors each time.
level 3, climb on top of a flying golem and finish him off with your rifle !
Clear a level while using all five traps.
Clear level 1 without using your rifle.
Get inside the foghorn.