And water is pretty hilarious - you can mine it with the pick, trees and leaves prevent water from flowing, and it falls *really* slowly. That's not criticism - I actually enjoyed that. Even though I'm pretty sure it's not the long term goal.

My one real (small) complaint is what happens when you dig/build/whatever, leave the area, and come back. Everything is reset. I assume the world isn't just generated in chunks, but also forgotten in chunks too. And I assume that isn't planned for the long term either.
Oh, and I also couldn't figure out how to use ropes. I got them placed, but can't figure out how to climb.