I've been working on a custom campaign for L4D2, together with aaWee, Goudvis and Doctor, which we're developing for more than a year now. We're in the stage where we're in need of feedback from the community, so we've put up a demo for the first out of five maps. Therefor, may I please ask all willing souls to test the map and let us know what you think about it? Everything helps at the moment. We're happy to see that people like the map, but we love negative feedback even more because then we know what to improve.
Here's a short description of the campaigns back-story: After travelling along the river for a few days, the four survivors tie their boat to a small dock along a canal in an unknown city. They are drawn here by radio messages indicating a possible military controlled outpost within the city. As they move deeper into the city, the military's plan becomes clear. Their only hope for salvation is to reach the outpost. They need to move fast, because when the clock stops ticking, the worldwide bombing of infected areas begins.