Here is the full list of all 20 Dungeon Rustlers achievements.
Make it to the 10th stage
Pick Up Special Attack For First Time
Mop Up 1000 slimes
Slay 1000 imps
Turn 1000 skeletons into piles of bones
Extinguish 1000 fire elementals
Drink 250 potions
Scoop Up 1,000,000 coins
Grab 1,000 point chests
Make 1,000 Runs
Use All 3 Bombs In Level 1
Defeat Stage 25
Kill Your First Death Knight
Play Level 1 For 1 Hour
Obtain 100 Extra Lives
Beat the first 25 levels in under 22 minutes
Beat the game 100 times
Slay 1974 Water Elementals
Kill 600 Enemies While Rushing
Play Through The Game Without Using Powerups