Here is the full list of all 12 Imagine Me achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Complete All Challenge Levels
Complete 50% of the Challenge Levels
Fall for the 15th Time
Falling into the Darkness
Defeat Three Bosses
Defeat Two Bosses
Defeat One Boss
Complete One Story Page
Pick lock your first door
Jump on a Trampoline 100 times
Move a Crate. Have an Achievement.
Begin a Dungeon in Campaign