This was a pretty solid puzzle game with cool visuals and sound design. I also liked how you incorporated a leaderboard for speedrunning incentives.
The game was pretty fair for the most part, but there were some occasions where you could softlock yourself in a way unrelated to the puzzle logic. Although having a reset key prevents you from getting fully softlocked, there were some instances (particularly in level 3), where I think you should have just let the player jump back out of the pit they got stuck in.
Other than that, the player feels really satisfying to jump around with, and the sound effects for keys/doors are perfect. I also think you did a really good job with the theming.