Nintendo and its partner, The Pokémon Company, have filed a lawsuit against the developers of the popular survival adventure game Palworld, accusing them of patent infringement.

Palworld gained the nickname “Pokémon with guns” after its first trailer premiered in 2021. Following the game’s launch in January of this year, The Pokémon Company announced it would investigate claims that Palworld was a copycat of the Pokémon series.

Pocketpair Inc., the developer of Palworld, has yet to respond to a request for comment from BBC News. However, the company’s CEO had previously stated that the game had passed legal scrutiny.

Nintendo and The Pokémon Company allege that Palworld “infringes multiple patent rights” and, in statements posted on their websites, announced the lawsuit. The legal action seeks an injunction to stop the infringement and demands compensation for damages.

Since its release, Palworld has garnered significant success, attracting over 25 million players within a month. Like the Pokémon video game series, Palworld focuses on collecting unique creatures with special abilities. Pocketpair promotes the game as incorporating elements of battle, monster-capturing, training, and base-building.

In Palworld, players, known as “pal-tamers,” explore a vast open world, battling both human enemies and creatures called “pals,” which can be captured and recruited. These pals can either help players in combat or work at a base to craft resources and items.

In January, The Pokémon Company acknowledged fans’ concerns about the similarities between the games and stated they would take “appropriate action” if their copyright was found to be violated.