A pretty fun experience! The core gameplay loop is simple but effective. The visuals and audio are also strong, although a SFX for when you land a hit on the enemies would be a nice touch too. I also enjoyed the skill tree as it is quite satisfying to see my lightning become stronger. I would like to see some more variety in gameplay too, because while the upgrades make the game more fun, I think having more to do on screen would benefit the game a lot! You could add other powers that could synergize with the lightning, or other abilities you can swap between to give the player more decisions during gameplay.
Otherwise, this is a well-polished game, great work!