http://www.minecraft.net/

Looks like its still in progress, but its still fun.
Basically you just walk around the place, you can build stuff up, or you can destroy stuff and make huge underground tunnels and passages. Have fun.

Oh btw, when loading the game, your browser sorta like freezes for a moment, but then goes back to normal.

Hehe, that's pretty fun. It reminds me of garry's mod without the physics engine... or melons... It's still great fun, though. Lots of stuff to do. I built a castle with a dungeon, keep, and walls. :D

I haven't tried the multiplayer yet, but I assume it might have some problems with griefers/abusers that just eat up the whole map and peoples' creations lol.

Lack of a good physics engine makes up for cool stuff. For example, you can build giant floating castles.

Multiplayer maps are pretty huge and awesome. They look like they were pulled out from some surreal fantasy or something like that because of the insane amount of things other people have built.

It's just not your boring, standard, gravity-based physics! :P

I like it!

Aye, very fun... but you still can't make a melon ICBM launched from a flying bathtub gun platform. This is very fun, though... Today I made a schooner.

Absolutely epic!

Edit: Just paid for foreverever :P

Nice... I like pressing 'f' a few times so you can't see 5 feet in front of you, then pretend you are in a zombie movie or something...