Were Minecraft a multiplayer FPS it would probably be Ace of Spades, a game coming to Steam in December.
Ace of Spades not only has a cutesy voxelly world like Minecraft, it has a build-anything-anywhere mantra too.
So while your team of 16 fights the other team of 16, you can knock together a fortress or dig a tunnel or erect some walls. And then you can shoot the enemy's hard work to smithereens.
Ace of Spades was indie-grown but since October had RuneScape house Jagex whipping it into shape. Looks like the graphics have improved, judging by the screenshots.
Ace of Spades has also been playable for a while in prototype form. Since April it's been downloaded 2.5 million times, and in September there were 550,000 active monthly users.
It was free then, of course - on Steam there will be a "small one-off fee".