No missable achievements (plus 16 unknown)
Sign in with Steam or Xbox to track your progress, and:
Break yourself 100 times
Unlock a second room
Break yourself 1000 times
Go completely first room
Unlock third room
Unlock character Cool Hardie
Unlock character Yellow Hardie
Unlock character Broken Hardie
Go completely third room
Unlock character Black Hardie
Go completely second room
30 times to drop into the acid
Meet the laser 30 times closer
Swim in the lava 30 times
Unlock all characters
Complete game