This is such a cute game. I love all the different avatars and their different abilities. The game becomes tougher as you advance in the levels, which is really engaging but can be frustrating at times when you or another player gets blocked somewhere for a while.
You mentioned this in your notes, but a death screen would be a valuable addition.
The levels feel cohesive and the sound design is good; I would just iron out the more challenging last steps so they feel more fluid.