This i really cool game and the concept of the level system is pretty cool, but i can see 2 flaws:
-the difficulty
-the time to die/respawn/go to another room
The difficulty is fine imo, but because of the second flaw it's a little bit frustrating, because you really wanna go into the next room but it takes like 30 seconds to go to where you were before you died.
If you would respawn instantly and the changing room animation was sped up too it would be a really cool die and retry game