Great game! I have very few complaints about it. The movement is by far the best part, dashing around with the left mouse is just so much fun. I also like your idea for the mechanic and make the player balance out the two attack modes. My one suggestion for improvement is to only exchange power if you hit an enemy, so that you can't just charge up the lightning attack by spam dashing around. It would reward the player for riskier gameplay. Overall, great job!