Robopon

Gameplay revolves around collecting, software upgrading, equipment swapping, and battling robotic characters called Robopon in a similar manner to the Pokémon game series. Robopon can be found in the wild and captured using magnets. To power up the Robopon, the player can add software and parts to them. Parts have varying amounts of space to store software and determine what sort of attacks the Robopon can use.

For example, a Robopon can have an "Armgun" or a "Punch" part, and its software can add one of 12 elemental attributes to the attacks, such as "Fire", "Thunder", "Holy", or "Sky". Furthermore, software can be added onto other parts, creating more powerful additions. For example, by equipping a "Thunder" software to a "Punch" part, the Robopon is able to use "Thunderpunch". ".

The player assumes the role of a child named Cody, whose grandpa is retiring and gives him the family business, a Robopon dispatching company. Cody travels around Porombo Island collecting Robopon and battling against the "Legend 7", the top-ranked Robopon collectors on the island. Each time Cody successfully beats one of the Legend 7, he takes his or her place in the ranking system.

In Famitsu, all four reviewers said the game was similar to Pokémon, with one saying it was a rip-off of the game while others believed it was still enjoyable despite its derivativeness. One reviewer complimented the use of the infrared remote while another said it was not used enough within the game. Craig Harris of IGN said Sun was a decent game, but played like a clone of Pokémon. Nintendo Power's reviewers called Sun "an unabashed Pokémon knock-off", lamenting the game's unoriginality. Ethan Einhorn of Electronic Gaming Monthly called it "the best Pokémon clone yet", but wished it had innovated on the Pokémon gameplay formula more, believing the GB Kiss features were "superfluous".

A 3D Robopon game, Robot Ponkottsu 64: Nanatsu no Umi no Caramel, was released in Japan for the Nintendo 64 on the same day as Moon Version. Players could transfer select Robopon between the GBC games and the N64 game using the Transfer Pak.

A sequel was released in Japan in 2001 for the Game Boy Advance, which was split between two versions like the original game: Robopon 2 Cross Version and Robopon 2 Ring Version. It features several gameplay changes from the original game, including the addition of four-on-four Robopon battles. Both versions were released in North America in 2002.