9-11 Survivor is a game mod based on the Unreal Game engine. It recreates the twin towers on September 11th, and places the player on a floor at random in one of the towers when the plane hits. The player has to find their way out: face masks protect you from smoke, cellphones can't dial out but can be used as light sources, water bottles restore health, and if you find a fireman you're saved.

Please say this is a joke...