It’s no secret that Valve is working on several projects at a time, but it’s a pretty big secret what those projects are. Besides Half Life 3, or Half Life 2 Episode 3, we dunno much of what’s going on, besides the occasional hats for Team Fortress 2.

But according to new evidence, the studio is working on a science fiction game with the codename “SOB”. From the recently leaked DOTA 2 code, there are several references to “ep3″, “cstrike2″, and “SOB”. According to one rumor, the SOB includes code references to “nebula”, “npc_ship”, “ship_guns”, “client_ship”, “flightplan”, “server_ship” and more. We’ve also gotten some concept art from one of Valve’s artists, who featured it on his website — the concept art of a space ship which you can see above.

Half Life protagonist Gordon Freeman carried a wide array of weapons, from the trusty crowbar, to rocket launchers, grenades, and what not. While most modern shooters today let you have only a few weapons, usually two main guns and a sidearm, older titles like Half Life let the player keep all weapons he finds throughout the game, hence the image of the real Gordon Freeman. We’d love to see how the real Duke Nukem looks like.

If there’s one game we’re all eagerly awaiting to see, it’s the next Half Life game. Whether it’s called “Episode 3″, or just “Half Life 3″, we wish Valve would announce something soon. And they may be closer to announcement that we think, as Half Life 3 t-shirts have been spotted being worn by a Valve employee at an industry event.

Now, this could be a hoax, it could be that the employee just got the t-shirt made for himself, it could be that it’s Valve trolling us — it could be a number of reasons why this doesn’t mean that Half Life 3 announcement is around the corner. But we really want it to be true.

Half Life 2 was released back in 2004, and got two small “sequels” in form of Episode 1 (2006) and Episode 2 (2007).

On this day, five years ago, one of the most critically acclaimed games was released: the sequel to Half Life, Half Life 2. The game was originally delayed for a year or so, after the source code was leaked and much of the game had to be rewritten. Since then, we’ve seen two expansions and a ton of mods. Half Life 2: Episode 3 is slated for release in 2010, with Half Life 3 coming in late 2012. Coolvibe has a great collection of early Half Life 2 concept art, worth checking out.