This is a simple concept that has great power!
And also seems to require a great deal of smart level design so it won't become a hassle to keep going back and forth to get all itens to be able to progress. That's the main issue I see with this game. Also I found a bug where, after quitting and re-opening the game, I pressed 'R' to restart and re-spawned way later in the level, and without any itens, so completely stuck. That was weird haha.
Feels good to play and is intuitive. Liked the music and simple sfxs as well. So nice job!