Last year, Valve released - for free - a game called Alien Swarm, which ended up with a visual style somewhere between the original Alien and a 1980s action figure. This early concept, though, shows something a little more unique.

Drawn by Valve environmental artist Ivan Simoncini, it depicts an early test for a "diorama" style appearance for the game. Seeing as Alien Swarm shipped with a tile-based level creation suite, this "model kit" look seems a natural fit for the pre-fab nature of the title, and seeing how cool it is makes me wish Valve had actually gone down this path with the game.

Ah well. We can always hope a future Warhammer game might look like this!

I've been playing a little Alien Swarm this week. It's a pretty good game as is, but that's not why it was provided free of charge. No, it was provided free of charge so you kids could mess with it.

And we're already seeing the fruits of these labours. Shrimpsess over on the Steam forums has posted a long list if command line tweaks you can make to the game, which with just a few characters can introduce a range of features other developers would be charging for as premium downloadable content.

Like the introduction of a "director mode", like the one found in Left 4 Dead, that intelligently spawns enemies. Or an actual, working first-person mode for the game. There are also some minor (though welcome) changes, like shifting the Gears-of-War-a-like "fast reload" system underneath your guy instead of hiding it in the corner and enabling 360 controller support.

List of useful Alien Swarm console commands [Steam, via PC Gamer]

As promised, Valve has released top-down co-op shooter Alien Swarm on Steam, free of charge. Have fun!

The Alien Swarm Unreal Tournament 2004 mod becomes a full, Source-powered four-player co-op tactics game, available for free on Steam this Monday, courtesy of the nice folks at Valve.

Valve hired on the team responsible for Alien Swarm two years ago. Since then, they've been busy working on the Left 4 Dead series and now Portal 2, but they've managed to squeeze out a little extra time to update Alien Swarm as a full Source release.

Alien Swarm is a top=-down four-player shooter, similar to arcade games of old. Players one of eight unique characters with four different classes, and battle their way through hordes of aliens using more than 40 different types of weapons and equi9pment. Players will gain levels as they play, unlocking persistent items along the way.

Not only is Valve releasing the game for free on Monday, it's releasing the game's entire code base and modding tools as well. With a simple, tile-based map editor, modders should have a field day with Alien Swarm.

Look for it on Steam come Monday!