Reddit user "Atheism4tw" has posted links to a Wiki as well as a playable demo of the in-progress title in a thread, identified as "CAPX" by the Wiki. The Wiki contains the game's entire Pokédex of "Fakemon," the moniker used to refer to its plethora of creatures, which sport names like "Pistol Shrimp" and "Chihaha."
According to Kotaku, 4chan's game appears to have been made with the Pokémon Essentials program, a collection of scripts and tools built specifically for fan-made Pokémon games. The game is set in a region called Urobos, with an environment inspired by South America. Players can choose to become one of two trainers, Simon or Sophia, and race to Pokémon training stardom against their rival Richardo.
Interested players can download the demo here.
4chan's previous foray into game development was Katawa Shoujo, a dating sim in which players chose to flirt and form relationships with various physically handicapped girls.