Here is the full list of all 11 Jomp The Jumper achievements.
You reached the game over screen for the first time
You finished the game on easy difficulty
You finished the game on medium difficulty
You finished the game on hard difficulty
You finished the game on insane difficulty
You finished the game on impossible difficulty
Finish the game on any difficulty (except impossible) without using any checkpoint
End the game without losing any life
You reached the game over screen ten times
You reached the game over screen one hundred times (are not you tired?)
Now you know what happened!