Nice work, I tried it today and I really like the climbing option. The two big cons actually for me is the empty world (no monsters or animals to interact with) and the crafting/inventory. I just did some recipe and without the starting help, I didn't understand what I was doing wrong, until I saw that I was using wood instead of stone. Also, each time that I put a stick in the middle and that I want to remove the top object (when crafting), the stick takes so much space that I need to put it away before moving the object on the top position.
Otherwise, it feels nice (and strange?) to evolve in the world of Minecraft. Good job !