Cool and very polished puzzle game! Overall the game is great, but there's too much repetition and artificial slowing down:
1) on level T2 you have to push the boxes really far. And you gotta do this twice. Personally, I realized the concept of blocks & buttons from the first glance, and it took me so long to implement my understanding and complete the level. I'd try to shorten the distance and check if it's possible to have only 1 box;
2) the level 8 is symmetrical, and after beating one half I had no interest in doing the other;
3) often you need to wait until the end of the loop because you're going to do a long stretch next cycle. Consider implementing so that you can hold Space for 0.5s and the actions will be decreasing very quickly.
Again, the game is pretty darn good, these are just suggestions to hopefully make it better!