I just saw your game on the GMTK livestream and had to give it a go, we made two very similar games. ;)
I really liked it, with some polishing of the physics I think this really can be something great.
Since you only have a limited amount of blocks I think picking up the blocks again should be restricted somehow, so you can't pick up the blocks behind the little quy and use them again. Maybe once the small player walked over them they get locked?
Some notes I took:
* There is no deadzone for controller movement, so you constantly drift around when using a controller
* The blocks collide with the giant so they sometimes hover in the air
* The yellow block can be placed inside of other objects to lock it into place
* More movement/rotation objects would be nice to make it easier to align them
Overall the game fits the theme nicely and it's fun to play, so great job!