The story revolves around the Planet Mischief, where there is a tradition that once someone turns 3-years old, he or she must travel to a planet and learn how to perform "Mischief" and cause panic on that planet. Cosmi, a three-year-old alien, travels to Earth for his mission, in order to impress his father, the Master of Mischief, Cosmi Sr., mostly because Earth is considered the greatest challenge. Cosmi crashes with a TV satellite from a town called Coco Town. When crash landing, he manages to hide in an alley on Coco Town, where he is saved by Earth's Mischief Master, Master Itazura. He takes him to his Dojo to train, and lets Cosmi move on with his mission, on 8 different locations: Coco Town, High Stakes Hill, Pranksylvania, Pharaoh Island, Big Booty Bay, Frontiersville, Raccoon City and finally Cosmopolis. It is revealed that Cosmopolis is a trap for "Anti-Alien-Forces" to capture all of the aliens on Earth by disguising themselves as aliens. Itazura uses their trap as the final challenge for Cosmi, and challenges him personally there. Cosmi wins and travels back to Planet Mischief to celebrate, but crashes into another TV-station and crashlands on Earth again, this time, in the middle of Coco Town square. Of course, panic arises and reporters try to get a snapshot of the little alien, but Cosmi accidentally pushes someones camera around, causing it to take a photo of the crowd, thus revealing that several of them are also aliens.
Gameplay
Since Cosmi is vulnerable in his small alien form, he must first beam up a nearby earthling in order to create a disguise for himself. Once he has beamed a person up, he can change his form by stepping under a UFO. Each earthling has a different ability that can be used for causing mischief, such as boomboxes, vacuum cleaners or bazookas. Successfully knocking over earthlings yields coins that are required to complete the goals set in each level. Once pranked, the earthlings will become hostile towards Cosmi and try to attack him. While disguised, Cosmi can take two hits, the first leaving him in underwear, while the second one reverts him to his vulnerable alien form. Earthlings will continue to chase and attack Cosmi, forcing him to lose coins, until he can find another UFO to change into another disguise. At certain points in the level, a Panic Time will occur where something crazy in the stage happens for a short amount of time.
Characters
Cosmi: The son of Cosmi. Sr, he considers himself to be a pro in mischief, even though he's clumsy and arrogant. He can transform himself into Super-Cosmi by using a special item. He thinks that Master Itazura should cool it down about worrying about him. Becky: The self-proclaimed friend of Cosmi. Cosmi considers her more of a nuisance rather than a friend, considering her obsession to be with him. She looks similar to Cosmi, but with white skin, blonde jelly-like hair with two snail-like eyes on top, a red dress, red boots, a red lady hat and white pants under her dress. She can teleport with a special item. But in the end, she becomes egotistical and demands that everyone should love her. Mumphy: He is quite the lovely baby of his family, and has not left his planet until now. His nickname is the "Ball of fire", which fits his appearance well. He is a robe-clad ball with eyes and a mouth, with pink skin colour and a feather on top. He is quite literally a hothead considering his special item that causes volcanic eruptions. In the end, his mother reveals that he is adopted, and shows him a picture of his real mother. Baron von Proptop: A vagabond of all trades, he travels from world to world to see new life and new civilisations but collapses from exhaustion when reaching Earth. He is saved by a friendly nun, and taken care of by her. He finds out that they suffer from an economical crisis so Proptop decides to thank the nun by winning the contest and giving the prize money to them. He wears a tall French-polis hat, with a propeller on top, a red scarf, goggles, green-jumpsuit with large sleeves etc. His special item causes everyone to tie themselves up and drop coins. In the end, he wins and returns to the nuns, leaving the money to them and continuing his travels without having them see him. The nun hears his propeller for the last time... Princess Cleo: A princess from her own world. She has never had a boyfriend and enters all kinds of competitions to raise her fame. Finally she enters the Mischief tests to try and raise her fame again. She looks like a mermaid with pink fish skin on her tail, pink hair, a very oddly shaped crown, a white trenchcoat and a human face. She can summon a UFO whenever she wants. In the end, she finds true happiness from witnessing Earth's vast oceans, and decides to spend her entire life in the sea. Magnetron: A genius in mechanics. He creates a large machine, which he operates called "Magnetron" for the contest. He himself is a small green blob with only one eye, a catlike mouth and a shell on top of his head. His robot has horns, goggles, a large clunky blue body, magnets for hands and small legs, and he can use a special item to drag in every coin for a time-limit. In the end, his success leads to the mass-production of his robots, and he becomes wealthy.
