One of my most anticipated games for this year is Left 4 Dead, Valve's Zombie Apocalypse game that's all about cooperative play. The thing is I haven't been able to try, and until this week no one has, is the Xbox 360 version of the game. I was worried that a Valve game built to be a PC experience would lose some of its luster when it hit the Xbox 360. So I sat down yesterday to play through one of the game's 20 or so maps.I was happy to find that Left 4 Dead on the Xbox 360 looks and feels pretty much like the PC experience. The controls are, of course, slightly tweaked, but in general the differences are negligible. The aiming, Valve's Chet Faliszek told me, includes a very slight auto-aim feature. Actually, it's more like a weighted aiming system, the game helps you lock on when you move the reticle toward a target and it's so subtle I didn't notice it even after I was told it existed. The designers also built in a 180 turn button (one of the bumpers) so you can quickly spin around to take on the ever present Zombie threat. Graphically the game looked fairly similar. I wasn't able to do a side-by-side comparison and I'm sure graphic snobs will notice a difference, but it wasn't anything jarring for me. After playing around with the 360 version of the game for a bit, I bugged Faliszek about the PlayStation 3. Why no PS3 version for the game, I asked. Faliszek said that it's mostly a matter of development time. Creating the Xbox 360 version of the game is close enough to creating the PC version that it's "almost like pushing an A button," he said. The PS3 version, though, essentially requires starting from scratch. That doesn't mean the game won't be coming to the PS3, but I suspect it will be awhile.