Here is the full list of all 16 2DGameManias Taken achievements.
COMPLETE TUTORIAL
COMPLETE BOSS #1
COMPLETE BOSS #2
COMPLETE BOSS #3
COMPLETE BOSS #4
COMPLETE GAME
GET A HIGH SCORE
COMPLETE GAME IN UNDER 60 MINS
COMPLETE GAME IN UNDER 50 MINS
COMPLETE GAME IN UNDER 40 MINS
FIND HIDDEN AREA
FIND 50 GOLDEN DIAMONDS
COMPLETE GAME IN UNDER 90MINS
FIND 256 GOLDEN DIAMONDS