I played for about 3.5 hours (on PC version) last night before passing out and I don't know where people are finding all these bugs from. Granted I haven't seen the Mammoth bug yet where it gets stuck in mid-air, but the UI is fine for me honestly. I'm using the mouse and keyboard and the scroll wheel works to go up and down in the menus, the moving and clicking the mouse works for me just fine. I seriously do not see "all the bugs" some are talking about in the game. Also someone complained about how to close a chest? Umm...hitting tab works.
Anyways, fantastic game and I am thoroughly impressed.