Pokémon Puzzle Challenge is a handheld companion piece to Pokémon Puzzle League. Whereas that version focuses on the Indigo League by way of the anime, this one is based on Pokémon Gold and Silver.
Players move blocks horizontally to match them. Three or more in a row of the same kind causes them to disappear. In some cases, an enemy (Gym Leader/Elite Four) Pokémon may cause havoc on a player's field, dropping garbage blocks and other effects.
The game was released in Japan as Pokémon Pan de pon for Game Boy Color on September 21, 2000. In December of that year, it released under its western title, Pokémon Puzzle Challenge, in the United States. The following year, it also released in Europe.
Throughout 2014, the game was released across the globe on Nintendo 3DS eShop's Virtual Console.
Hidden Panel de Pon
Using a button code, players can access an unfinished version of Panel de Pon. The game has never been released in that form for Game Boy, so the best guess from researchers is that it was a port that was switched into a Pokémon themed version relatively early in development.