Polished game with a really clever and simple mechanic! I almost made it through without hints, though that last level gave me a headache ^^
I also really like the style and the relaxing music. The amount of levels is impressive. I feel like you could have done even more with the scaling mechanic, like levels where you need to use only part of the size change. A tile only expands until it gets blocked so for example your tiles scale by 3 steps, but you need to scale one of them only by 2 (it happened once but looking at the hint afterwards I didn't use your solution).