Here is the full list of all 12 WonderCat Adventures achievements.
Get all crystals on World 5
Get all crystals !
Defeat boss in Elemental Chambers
Get all crystals on World 4
Get all crystals on World 3
Defeat boss in Molten Core mines
Defeat boss in Toxic Pipes
Win level 3.3 in less than 20 seconds
Get all crystals on World 2
Defeat boss in Clouds world
Get all crystals on World 1
Defeat the boss in Old Crystal Mine