Indie dev Unknown Worlds have released the first still images from their hotly anticipated Natural Selection 2, the retail sequel to the much-loved 2002 Half-Life modification.

There is nothing touched-up in these shots. Like editing with our tools, what you see is what you get! We hope you enjoy the style and direction we're going in and these give you little flutters in your belly (excitement, that is).

These new images offer a glimpse at players in both the space marine and alien factions, the later being the view from the alien Skulk class's "bite-cam". They're also accompanied by a detailed blog on the state of the game from the dev team.

Natural Selection 2 is now positioning for a 2010 release on PC via Steam.