Some really nice juice in this one! Liked how the color shifts between the different sizes.
If I can give one suggestion it would be to let the player push the boxes when they are big enough without breaking contact with them, since if you start pushing and then grow, you have to stop pushing and then push again for the game to register that you are now the correct size.
Also, holy smokes that soundtrack is fire. Specially dig the main menu music. Good stuff!