Left 4 Dead is a survival horror FPS video game developed and published by Valve Corporation. It was released in October 2008. The game takes place after the occurrence of an apocalyptic plague. The storyline revolves around the four protagonists in the game called the Survivors as they try to stay alive by fighting off hordes of infected humans.
There are four gameplay modes in L4D – Cooperative Campaign mode, Survival, Versus Campaign and Single-Player.
• Coop Campaign – This mode is composed of up to four players. Their goal is to reach the safe rooms safely then eventually getting rescue from the horde of infected humans. There is a special infected type in this mode, which is controlled by the AI.
• Single Player – This mode enables a single player to play the game. Its structure and flow is similar to the Coop Campaign mode. The only difference is that the other three players are AIs.
• Survival – This mode is completed within a certain time. Players’ goal is to survive for as long as they can against unlimited infected.
• Versus Campaign mode– In this mode, two teams go against each other. Each team may consist of one to four players. The teams play as both the survivors and the infected exchanging sides each chapter. The goal of this mode is to accumulate as many points after all the chapters. The team with the most points wins the game.