The character being knocked back furiously in a incontrollable way when hit combined with the hard to see spikes creates cheap death moments like this room(when returning from above).
Lighting while being cool also creates a lot of moments where its very easy to stumble into the dark slimes combined with the dark parts of the map.
The slide being slimy at the end also makes navigating the insta death pits (which also have large hitboxes) which require precise movements feels bad/unfair/frustrating.

The key counter being at the top takes a lot of space and also creates more cheap deaths moment,which would probably be better if it was in the cornors.

Not having to deal with pits makes the boss fights the most enjoyable part of the game as they provide a good amount of challenge with positive feedback(until you die and get sent back to the checkpoint all the way back at the top left of the map.
