Barely more than six months ago, Valve released Left 4 Dead, a first-person, zombie-shooting game characterized by the quality the developer is known for. Players choose one of four characters, and make their way to saferooms located throughout the city, aided by the game's AI, known as "the Director." The AI decides the position and number of enemies, weapons and items throughout a level, ensuring a completely different (and never boring) experience each time you play. Perhaps what makes L4D most unique, though, is the depth of the co-op experience. Even playing solo, you rely on your fellow survivors to free you from the grasp of certain zombies, pull you up from a ledge or share their supplies when you're starting to drag.

Though an exhilarating experience, the game's content was scant upon its release: four campaigns, each about an hour long, only two of which were available for play in "versus" mode. However, this didn't stop L4D from receiving praise left and right; bare bones games are a hallmark of Valve, who prefer to gradually add new content throughout a game's lifespan. This kind of multi-course delivery serves to keep players playing, and allows the developers to respond to fan feedback. The formula has proven especially effective for Team Fortress 2, another Valve title released a little over a year before L4D, and still thriving on periodic content updates.

Which is why many gamers are shocked at the recent E3 announcement that a Left 4 Dead 2 is in the works, and due out this year. So far, we've been told that a new cast of survivors (which seems to include Fresh Prince's Uncle Phil) will star, making use of new weapons, items and maps, and even facing new zombies. A generation ago, this might have made sense: a better, shinier sequel featuring everything you couldn't fit into the original.

But the nature of the upgrades, and especially the timing, have everyone scratching their heads. Left 4 Dead is still incomplete, and this is exactly the kind of content that it needs to flesh it out. Further, the highly-successful game is probably still years away from petering out; there is no demand, let alone any need, for a sequel just yet. The most likely explanation would be a financial one, but Valve is alive and thriving, and have never been known to abandon a game with such a large user base.

So why? Why is Valve, a successful and beloved developer, brushing off a flourishing game six months after release to deliver an unwanted sequel? Why isn't this content being put into L4D, where it's desperately needed? E3 is supposed to answer questions and pique our curiosity, not raise suspicions and cause mass confusion. With any luck, fans will receive reassurance following further news on L4D2, and this won't just be one big let-down.