My favorite video games allow you to share the experience with other players. This sentiment doesn't only apply to multiplayer games but also to single-player games that encourage interaction between players. I often refer to them as Kodomo games because of their prominence in Kodomo manga magazines like CoroCoro Comic, Comic BomBom, and V Jump. For example, CoroCoro Comic has featured many video game franchises, including Pokémon and Mega Man Battle Network. Kodomo manga magazines promote these games with articles and manga adaptations like Pokémon Adventures. However, Kodomo games aren't defined by being prominent in Kodomo manga magazines but rather by three distinct qualities.
One quality of a Kodomo game is an immersive world that players can imagine themselves in. An immersive world requires a protagonist and setting that is believable to the player. A protagonist that is a blank slate makes for a better avatar because they function as nothing more than a stand-in for the player. A setting that alludes to other characters with the same abilities as the protagonist makes the idea of other players inhabiting the world more reasonable. Pokémon is an excellent example because it has both a silent protagonist and a world populated with other Pokémon Trainers. Worldbuilding also contributes to creating an immersive world, like how the technology and culture of Pokémon are reflective of its fantasy elements. Establishing a connection between reality and the game world is another aspect that makes a setting more immersive. Boktai establishes this connection with its real-time clock that dictates the time of day and solar sensor that alters the game world based on the amount of sunlight striking the game cartridge.
Player expression is another quality of Kodomo games and usually manifests as collectibles. These collectibles can be monsters, robots, cards, etc. what matters is the player's ability to decide which ones they want to use. The more collectibles there are, the more the player can express themselves, leading to a more personal experience. Offering various methods to acquire these collectibles ensures that if players engage with the game differently, they will have unique collectibles. Additionally, some of these collectibles should have an air of mystery to encourage speculation amongst players about the means of obtaining them. Dragon Quest Monsters achieves this with its robust breeding system that occasionally combines two monsters into an unknown species. While in Keitai Denjuu Telefang, there are three types of evolution (natural, fusion, and lab), leading to some monsters having branching evolution trees. Keitai Denjuu Telefang also included secret monsters that you can call by dialing in-game phone numbers revealed in issues of Comic BomBom.
Playing together is a quality of Kodomo games that isn't limited to multiplayer modes. One compelling way to play together is the Azure Sky Tower, a 99-floor dungeon in Boktai: The Sun is in Your Hand that bestows each player with one of four elemental Emblems. The only way to complete the Azure Sky Tower is by collecting every Emblem by swapping them with other players through the Emblem Resonance feature. Another compelling way of playing together is the BrotherBand in Mega Man Star Force 3, which allows you to merge your Noise Change with a friend's. A Noise Change is a transformation Mega Man receives partway through the game that grants him an elemental affinity, a more powerful Mega Buster, and passive abilities. However, in my opinion, the best way to play together is through multiplayer modes that provide opportunities for competitive and cooperative play. A great example of this is Gaist Crusher's multiplayer, which lets up to four players participate in team battles and co-op missions.