Pretty fun game. It can be difficult to see exactly which circles are tagged and which aren't, as well as the circles themselves. The slide movement does feel great, as well as the SFX when you hit something. For level design, I would recommend lowering the amount of slides for some of the levels to 10-20: 50 slides can be fatiguing especially if it's just doing the same thing over and over again.
Puzzle games can be hard to make, but this is a great start. Good work.