Here is the full list of all 36 Platformity achievements.
You completed the game on normal mode
You completed the game on hard mode
You completed the game on HC mode
You completed the chapter 1 on normal mode
You completed the chapter 2 on normal mode
You completed the chapter 3 on normal mode
You completed the chapter 4 on normal mode
You completed the chapter 5 on normal mode
You completed the chapter 6 on normal mode
You completed the chapter 7 on normal mode
You completed the chapter 8 on normal mode
You completed the chapter 9 on normal mode
You completed the chapter 10 on normal mode
You completed the chapter 1 on hard mode
You completed the chapter 2 on hard mode
You completed the chapter 3 on hard mode
You completed the chapter 4 on hard mode
You completed the chapter 5 on hard mode
You completed the chapter 6 on hard mode
You completed the chapter 7 on hard mode
You completed the chapter 8 on hard mode
You completed the chapter 9 on hard mode
You completed the chapter 10 on hard mode
You completed the chapter 1 on HC mode
You completed the chapter 2 on HC mode
You completed the chapter 3 on HC mode
You completed the chapter 4 on HC mode
You completed the chapter 5 on HC mode
You completed the chapter 6 on HC mode
You completed the chapter 7 on HC mode
You completed the chapter 8 on HC mode
You completed the chapter 9 on HC mode
You completed the chapter 10 on HC mode
You bought your first hat!
You bought all the hats!
You have completed all the achievements!