Taking place at nine fictional locations between 1935 and 2035, the story follows 18 characters' individual attempts at defeating their own foes and the "TimeSplitters" with whom they have sided. In each level, the player can choose from one of two characters specific to each mission, and must kill enemies as they move through the level to retrieve an object and then carry that object to the exit portal. After a player picks up the object, TimeSplitters, evil mutant creatures, spawn endlessly throughout the level and attack the player.