Left 4 Dead DLC will arrive before April 21

In a recent interview with IGN, Valve announced that the Left 4 Dead DLC will arrive on both PC and Xbox 360 sometime before April 21.What makes April 21 such a special day for Valve? That is when the Left 4 Dead: Critics Choice Edition re-release hits stores.

The free L4D update adds both Dead Air and Death Toll to Versus mode as well as adding a new “Survival” mode. Apparently there will be 12 maps for Survival mode, 11 of which are recycled from the four campaigns. The one new map is called Lighthouse.

The way Survival mode works is, players will have unlimited time to search the level for better equipment without being harassed by swarms of zombies. Once everyone is outfitted to their liking, the players will trigger the zombie horde. Players will be faced with a never ending wave of zombies, both regular and special. To make matters worse, the classic limit on special zombies is gone, making it possible to fight two tanks at once. According to Valve none of it’s testers survived more than nine minutes.

Read: Left 4 Dead DLC Coming Before April 21.