The visuals and the atmosphere are just awesome. You did really good work with the shader. The game is really juicy with lightning and smooth animations. The fighting felt really satisfying
The sound was really nice : music fits the atmosphere, and SFX sounds good (I don't know if it's a mistake, but the Cloud Dash plays a different sound if it's used with the Spacebar.
Hitting the lightning ball was really fun !
The only problem in my opinion : there isn't a real goal. The game can be endless, but adding some health and damage is the only improvement I can imagine for your game.
Amazing work !