Wonderswan was a small handheld console by Bandai. The device wasn't popular in Japan and was a commercial failure outside of the region. But for Digimon fans, this handheld was the best handheld to have in early 2000's. Many Digimon games released for Wonderswan that were tie-ins to the anime that was airing at the time. The connection between all the games and the anime was Ryo.
For those familiar with Digimon Tamers anime, Ryo is one of the main characters in the second half of the series. He was introduced halfway through Digimon Tamers in the anime but his origin was from the Digimon Adventure universe and his story was told in form of a trilogy of games. It all started with the game: Anode/Cathode Tamer.
Digimon Adventure: Anode/Cathode Tamer are two games for Wonderswan. That were later remade as a one game on Wonderswan Color. The game is one of two Digimon games on the system that were released in English. (The game still didn't see a west release though. It was an Asian English version.) Anode/Cathode Tamer had three sequels. The final game Brave Tamer bridges the worlds of the first and third Digimon anime series, and establishes the existence of the multiverse. Each entry has changed the gameplay somewhat.
The story of Anode/Cathode Tamer follows the quest Ryo, a boy who was summoned to the Digital World by Taichi's Agumon to save the the main characters of the first season of the anime (The Digi-destined.)
Ryo befriends a lot of Digimon and fights many of the villains from the first season (Devimon, Etemon, Piedmon... etc.) Those villains were summoned by Millenniummon who will become Ryo's nemesis through all of his story spanning multiple games.
The gameplay of Digimon Anode/Cathode Tamer is a tactical RPG based, in which you control 3 Digimon to move them around the grid and use skills to defeat the enemy's team.
One interesting thing about this game, that instead of showing the Damage taken by attack. The game shows the attacked Digimon's remaining health.
Digivolution usually happens in form of special moves called Variables, in which the partner or enemy Digimon digivolve for one hit/special effect then turns back to his/her original form. This system is different than most other Digimon games as in the majority Digivolving is semi-permanent.
While Ryo doesn't have a partner himself, he befriends and commands many Digimon in his journey. Other than battles, you would collect Digimon. There are 180+ Digimon in the game, most are obtainable either as partners or as variables.
I think the story of Anode/Cathode Tamer is short and simple and I might say not that interesting. The appeal of the game is Digimon collecting and meeting with the protagonists from the anime. It feels nice to save them, you know?
While I think this game is a forgotten classics (especially since the console itself is a forgotten handheld,) I believe it's not for everyone. I guess only hardcore fans of Digimon who want to see where it all started (or just Ryo fans who want more of him) might fully enjoy this experience.
With the release of the anime reboot of Digimon Adventure (which is just called Digimon Adventure:) I believe now is the best time for Digimon fans to experience Digimon Adventures: Anode/Cathode tamer. Just make in mind that while the anime reboot shares characters, the story is completely different than the original which you must experience before playing any of Ryo's Wonderswan games!