Pretty good idea! Challenging and interesting. Here is some constructive feedback:
- It starts off a bit too slow, which makes it demotivating to replay once you lose
- It's kind of disorienting to have the circle shrink when you make a loop. It might help if you ease the shrinking process with a smooth animation between the two sizes.
- Of course, a rhythm game would be improved with some music or a beat to match your rhythm to! It would also be fun to hear the music speed up.