• AI Director 2.0: Advanced technology dubbed “The AI Director” drove L4D’s unique gameplay – customizing enemy population, effects, and music, based upon the players’ performance. L4D 2 features “The AI Director 2.0” which expands the Director’s ability to customize level layout, world objects, weather, and lighting to reflect different times of day.
• New melee weapons – axe, chainsaw, frying pan, baseball bat – allow you to get up close with the zombies
• Four different survivors. New Story. New dialogue.
• More game. On day one, L4D 2 features more co-operative campaigns, more campaigns and maps for the Versus game modes than L4D 1, plus support for Survival mode out of the box.
• Stats, rankings, and awards system drives collaborative play