I decided to quit after I beat level 3. I think the balancing is a bit rough, I had to grind level 1 to beat level 2. Although I did beat level 3 right after level 2 without grinding. Level 3 felt very very long for what was in it. So maybe make it a bit shorter, and make the upgrading easier or more powerful. The actual game was pretty decent, and there is a lot here which is cool. Would have liked to see different songs for the different levels, and the music didn't seem to match the game very well, but that first thing is really just a suggestion. So really I would say make the game a bit less repetitive, shorten levels to keep them under 3 minutes (or make them more dynamic in those 3 minutes), make progression a bit easier, and maybe work on the music a bit. Overall great job, and the art was quite nice