So I'm an idiot and didn't pre-order Left 4 Dead 2, meaning that I had to line up (virtually) with all the other plebes to download the demo today. But after spending some quality time with Valve's latest co-op splatterfest, I have to say that it improves on the original in virtually every way imaginable.
Yes, this game is a sequel, but you know what? It does for the original what Terminator 2 did for Terminator - expands upon everything that the original did right with bigger everything. The most notable change is the vast increase in weapons - now there are far more tools for your survivor to wield as they batter back the undead hordes. Melee is a new addition to the series, and while they close-range weapons can sometimes feel a little overpowered, I think the risk-reward mechanism attached to them is about right. Sure, you can knock a zombie's block off with an electric guitar in one swing, but that means you let him get close to you. And if one's close, more can't be far behind. Throw in new guns and new tools like the defibrillator and the level of strategic engagement that players can expect grows a lot.
The new Infected make an appearance as well, with varying results. I love the Spitters, who can scatter a group with gobs of airborne venom, but the Jockeys seemed a little weak - true, being ridden by a Jockey is terrifying, but a good group will pick it off your head within seconds. This is a minor quibble, of course, as I'm sure the difficulty balancing in the released game will bring the threat out of all of the enemies.
Most interesting to me is the new variations that the game's Director can throw at you to spice things up. In the previous games, the AI's control over events was limited to enemy spawn rates and density, but now way more is modular - from terrain and item distribution to special events such as surviving hordes of attackers to navigating mazelike areas. They add some much-needed variety to the game's flow and I can't wait to see more.