Great submission you guys! As Blob already said, I think it would be a good idea to hint to the player that only the saturated bits are solid in the 3D world (it took me longer to figure out than I'd like to admit haha).
Also, a way to restart only the 3D run would be nice, since I sometimes dropped down and couldnt get back up, although I had built the right solution of the level. And also there are ways of cheesing the levels by abusing that one bug where you can still move blocks shortly after they are meant to be placed down.
Awesome job overall!