The restricted use of colour and contrast really helps bring the focus to the key elements of gameplay - really like that.
Interacting with the different parts of the game was very clear, and taught the the player quite well!
Using health as a form of turn currency, where you're forced to spend it to get past enemies is an excellent mechanic! Made the gameplay a great mix of platformer combat and puzzle.
Tapping the arrow keys to cover long distances can get a little repetitive though!