Here is the full list of all 19 The World's Hardest Game 3D World achievements.
Enter The Forest.
Enter Snowy.
Enter The Desert.
Enter Darkness.
Enter Invisible.
Reach Level 2.
Reach Level 5.
Reach Level 8.
Reach Level 10.
Put on the Crown.
Die 10 times.
Die 50 times.
Die 100 times.
Die 200 times.
Die 500 times.
Die 1000 times.
Die 2500 times.
Die 5000 times.
Achieve the IMPOSSIBLE.