[2] Survival mode has been compared to the gameplay of classic arcade games, where players face off against increasingly stronger waves of enemies.
[5] Survival mode is particularly common among tower defense games, such as Plants vs.
[6] where the player must improve the defenses of a specific location in order to repel enemy forces for as long as possible.
[7] Power Instinct, released in 1993, added a survival game mode, called 'Life Attack' to their Super Nintendo Port in November 1993.
[citation needed] Killing Floor, originally a total conversion mod for the game Unreal Tournament 2004, first released in 2005, introduced the cooperative wave-based survival game mode.