Nice game! I really like the aesthetic and how the bosses have personalities to them. The music is also really good, and the last boss really felt like a last boss when he declares that he can go all out now. I liked the implementations of the abilities, and while the reflect ability is clearly the focus of the game, the bosses are well-designed around you getting the next ability.
If I could comment a couple of things, the transition when changing powers sometimes felt a bit... slow? Like, I change to flight, press space, but sometimes it feels like it takes longer to fly than others, but it may be just me. Also, is there a reason why you can't sprint when using Frost? Is it for balance reasons, since Frost gets the combo attack? You can sprint when using both Reflect and Flight, and it felt jarring changing to Frost and not being able to sprint, because I would shoot at Speed, freeze it, then try to run to land a combo aaaand... I'm walking.
Other than that, the game feels great, really good job!