Okay that was a really cool core mechanic. The idea of having the player zoom in or out to change their size relative to the world is really nifty and worked well. My favorite part was breaking the blocks to go through the roof! I genuinely wish I had thought to do that in my game.
My feedback:
I think that perhaps the magnification mechanic could be a bit more streamlined. In sections where multiple magnifications are required it can get a lil repetitive having to click multiple times. Maybe you could have the player pull up the magnifying glass and use the middle mouse button to zoom in or out.
Regardless, nice work! I liked the ending a lot haha.