Game Freak, the developer of Pokémon, in a statement confirmed its servers were hacked in August which led to a leak of sensitive employee information. The data leak also exposed beta designs, source code for games and details on upcoming titles.

Overall, the leak is estimated to have data going as far back as 30 years, with tidbits about the history of Pokémon, including the source code for beloved titles being exposed.

Game Freak is an independent developer which works in collaboration with both Nintendo and The Pokémon Company.

The company acknowledged the leak after documents and images of internal data started appearing on social media platforms including X and Reddit.

Dubbed the “Teraleak” files on social media, the data includes source codes for past games such as Pokémon HeartGold and SoulSilver, codenames for the Switch 2 and the upcoming Gen 10 Pokémon games — “Ounce” and “Gaia,” respectively.

The data also includes references to an in-development Pokémon MMO, and discussions from the company’s meetings.

While neither Nintendo nor The Pokemon Company have publicly acknowledged the leak yet, Game Freak said it is strengthening its security and apologised to those affected by the breach.