Here is the full list of all 21 Bit Heroes achievements.
Collect 100 Different Familiars
Reach Level 200
Reach Level 20
Reach Level 50
Reach Level 100
Collect 5 Different Familiars
Collect 20 Different Familiars
Collect 50 Different Familiars
Defeat Lord Cerulean
Defeat Gemm
Defeat Quirrel
Defeat Kov'alg
Collect 5 Quest Stars
Collect 15 Quest Stars
Collect 30 Quest Stars
Collect 50 Quest Stars
Make a fusion
Add a friend
Join a Guild
Reach Level 5
Collect 1 Familiar