Preface:
So, I've been working with someone on a game over the last while, me doing the art and him doing the code, and we've finally got it to a point where we're happy to let the public have at it; there's still bugs, but when you find them we'll try to clean them up as quickly as possible - report them in the blogs comments if you'd be so kind.
King Arthur's gold is a 2D multiplayer-only free "minecraftlike" in the broadest sense, where players fight for gold and land, building castles and digging out tunnels. Gameplay is open-ended and servers can be hosted by anyone.
The game is in the early stages (~4 weeks in now, I think) and we've just gone public!
Here's how you play:

Have at it, Metanet folk! I await your feedback :)