Some of you might have seen 'Ace of Spades' on Steam at the moment. The older version (which is very different) is still up at this site:
So if you want to play it, or you miss the original, just register and then download the game. Click 'Hot to play' for instructions on how to get the game working.
For those who don't know, Ace of Spades is a first person shooter in the style of minecraft. You have four tools:
Spade, to dig with.
Blocks, to make defenses or whatever.
A gun. Thee choices here, the rifle (one shot head, 3 shots body), the SMG (lots of shots... to anywhere), the shotgun (point, click, boom)
Three grenades, these can be used for tunneling too.
Anyway you should check it out, especially because it's free, I find it quite entertaining although it's a slow paced game and not everybody will like its style.