There's actually a whole lot more to the Alpha. You can create custom maps, fight and kill enemies, create races, ect. It's surprisingly great for being so early.
EDIT:
I shot gameplay of combat, which I am going to upload really soon. The first video was meant to show off its physics.
Next video I will record will be for map creation, so you all can see that. Though, you can always check out Wolfire's YouTube channel, too(which I think is on their website I posted).
EDIT 2:
And here's the new video;
http://www.decisive-media.net/index.php?action=media;sa=item;in=159