The Amusement Park is where the fourth mission of Metal Slug 4 takes place.
For unknown reasons, the Rebel Army has taken control of the place during the night. When the player is sent to investigate, he will discover that they are carrying experiments that consist on testing a substance synthetized from the mummy´s breath and zombie´s fluids on the people who were attending the park. Due to the nature of the two main attractions "Cursed tomb of the pharaon" and "Town of the living dead", it is understandable why there were visitors at night. Here the player can ride the Walking Machine, (a vehicle that resembles the Mutated Soldiers from past games) which is armed with two vulcan guns and grants high-jumping abilities. After some path is covered, there will be two routes to be followed by the player: one which goes down and the other goes up.
Cursed tomb route: if chosen, this path will take the player down and to advance through an egyptian-like attraction called The King´s Curse" where many people had been turned into Mummies by a substance that soldiers with green suits throw inside of rolling bombs.
Living dead route: if the player goes up the stairs, he will enter to "The Haunted Persons Town" a devastated city-like attraction where people were turned into Zombies by another substance which is thrown by orange color suited soldiers.
In both routes, the Walking Machine can be mounted but will become useless after a certain distance is covered.
All routes will eventually lead to the Big John boss battle