Damn, this is crazy polished, hard to believe it was made in such a short time.
Loved the drawings during the intro, very nice art style overall.
Whoever designed the levels is very good, there's a ton of smart uses of the mechanics. Plus the game really clicked once you added a second material for the digging, I hope you add more in the future!
Amazing project.
I think it'd be nice if you could go directly from one material to another, eg. in this place :
If there was some dirt instead of the 2 "black squares" you could dig up directly into the sand while staying burrowed. Wouldn't change anything here but could be interesting for other puzzles.
(Also as you can see there's a bug where you duplicate the sprite if you dig really fast... but I really enjoyed that you could go super fast by pressing the button fast :P)
I managed to get surprisingly far into the area with invisible platforms with guesswork, but finally got stuck here:
