What an awesome game!
I loved the idea and the level design, the gameplay is very solid and engaging,
I was always thinking weather to get bigger or smaller, and the same situation could be approached in different ways.
Switch size mid air is a really good feature, it opens so many opportunities for both players and designers.
The gameplay is the best interpretation of the theme I've seen so far, so simple yet so elegant.
The only downside are the visuals which are not as good as the rest of the game, but you said you made it in 48 hours so I totally understand. I made mine in 72 hours and I had no time for audio.
Good job!