Great job overall! The graphics and audio fit very well into the game, with the exception of a couple of sound effects that were too loud.
The major downfall for me was the lighting. It was very hard to see, even with the light option, in suboptimal viewing conditions, and I don't think I would have even needed the light option (which drains mana) had my screen been a little brighter. I think it would have been just as effective to brighten up the scene and keep the glow effect on permanently (without draining mana.)
I also wanted to mention that the jumping physics felt a little janky. It seemed like you invert the y velocity when the player stops holding the jump key -- I think it would have felt more natural to subtract a certain amount of velocity each frame. This point is pretty nitpicky though, it didn't really impact the gameplay once I got used to it.
I don't mean to be super critical -- it's a really nice game! I just wanted to say how you could improve it, and perhaps to keep in mind for future games too!