Long ago, the seas were ruled by treasure-seeking pirates. The most famous of these was the legendary Captain Maverick. He supposedly left a great treasure known as "Marvelous", guarded by unsolveable puzzles and bizarre creatures. Countless adventurers have gone looking for the "Marvelous", but none have seen it and returned alive...
Many years later, a group of children on a field trip landed on the island, which was rumored to house the "Marvelous". Unfortunately, so did a group of pirates who will do anything to find the treasure...
Dion (ディオン) (in red and brown; age 12) - He is short but spirited. He's a fast runner and a good pitcher. His small size allows him to get into places where the other two boys won't fit. Putting him at the head of the team will make them walk faster.
Max (マックス) (in green; age 12) - He is the largest and strongest of the three. He likes to eat, but also likes to play soccer and swim. He is also a good boxer. He can also lift up heavy objects.
Jack (ジャック) (in blue and red; age 12) - He is the smartest of the three. He's good with his hands. He likes to build things and work with machines. He's a good jumper. He's taller than the others, which comes in handy if the player needs to get to something high.
Ms. Gina (ジーナ先生) - She is the teacher of the three boys. She gave the boys a Leader Hat, which looks like a cowboy hat, but it helps them know who leads the group. She also gave them a Whistle, which allows the leader to call and bring the other two boys back to him.
Marvelous was influenced by The Legend of Zelda: A Link to the Past. The player controls three boys across the land by the bird's-eye view. A command window will pop up whenever the player encounter an object or person. The window will give the player choices on what to do with the person or thing, like picking up objects, talking, or reading.