Nintendo and its partner The Pokémon Company have filed a legal case against the maker of the hit survival adventure game Palworld over alleged patent infringement.

Palworld quickly earned the nickname “Pokémon with guns” when its first trailer was unveiled in 2021.

Just days after the game’s release in January this year, The Pokémon Company said it would investigate the copycat claims.

Palworld’s developer, Pocketpair Inc, did not immediately reply to a BBC News request for comment. Pocketpair’s boss previously said the game had passed legal checks.

Palworld “infringes multiple patent rights”, Nintendo and The Pokémon Company said in statements posted on their websites.

“This lawsuit seeks an injunction against infringement and compensation for damages”.

Palworld has become a major hit, with more than 25 million players within a month of its release.

Like the popular franchise of Pokémon video games, it also centres around collecting strange creatures with different powers.

Pocketpair’s website describes the game as seamlessly integrating “elements of battle, monster-capturing, training, and base building.”

Players, known as “pal-tamers”, travel around a large map battling human foes and creatures known as “pals” which can be captured and recruited.

The monsters can either fight alongside the player in battles, or be put to work at a base, crafting supplies and items for use in the field.

In January, The Pokémon Company said it planned to investigate claims that Palworld had copied its games, after fans pointed out similarities.

The Pokémon Company said at the time it would take “appropriate action” if it found its copyright had been breached.