I like that you included a scale indicator UI in this one. That is something I have recommended to a lot of other similar games. I also like how you allowed the player character to walk on different layers of the platform at smaller scale.
I did find some issues; the large projectile you have to scale down, for example, seemed to jump around when you scale it, so instead of making it small enough to go under, I just had to time it so the transform position changed in a way that it was behind me. I also managed to win the game somehow by jumping on spikes!
Overall, it's a solid effort with an interesting use of the theme. I think it's a really difficult design problem to solve to make these types of games fun and not frustrating at various scales.