Humans are being tested as Guinea pigs as part of a mad scientists experiment. In the arena are high voltage transformers that sends deadly waves of electricity upon activation. There are rising platforms which standing on them will save you from being fried turkey. There are also circuits in the field that have electrical bolts traveling across which deals massive damage to a player that comes in contact with it.
When a player dies they become sealed in a chamber and held prisoner until they're released by the scientist (alpha zombie).
The alpha will have many switches to rise the platforms in a variety of patterns. After enough switches are used, the main switch to release the zombies is accessible.