Buzz Killington, classy as fuck. I agree, the game feels pretty polished for an alpha. Only things lacking so far is music and sound effects, and the ability to interact with objects and NPCs. Aside from that it's pretty much exactly what I wanted.
As for multiplayer, I don't have the ability to run my own server, and the servers I've found all worked terribly, so I think multiplayer won't happen for a while. I think Ray had plans to host a GLG Cube World server, so hopefully that'll work out soon.