Here is the full list of all 15 Dungeonball achievements.
Complete level 2
Complete level 1
Pick up a slime
Complete level 3
Complete level 4
Complete level 5
Beat level 1 within 2 minutes
Beat level 2 within 2 minutes
Beat level 3 within 3 minutes
Beat level 4 within 3 minutes
Beat level 5 within 4 minutes
Reach loop 1
Reach loop 2
Get killed by a slime
Catch a fireball