Full list of all 10 140 achievements worth 1,000 gamerscore. It takes around 5-6 hours to unlock all of the achievements on Xbox One.
Achievements they've won
Achievements they've not won
Complete the first mirror stage
Beat the first boss without jumping.
Complete the game
Beat the third boss without dying.
Complete the second stage
Beat the second boss without dying.
Complete the first stage
Complete the second mirror stage
Complete all mirror stages
Die 63 times.