Neat game! Kinda calming in a way lol ( the soundtrack and sfx are great). Spinning around to charge planets that act as defensive towers is definitely a creative idea that I like. The spinning around is kinda hard to do sometimes but most of the time it's okay. As others said, yeah the difficulty jump in 3 level is big and the planets are kinda squishy, I only got left with jupiter so I had to frantically spin around the planet and try to hit some of the faster objects lol.
(The tutorial had some bugs where I clicked earth or jupiter and the game went to a black screen)
Overall cool concept, I can see it being a chill game with some more work :)