The makers of a video game dismissed as "Pokemon with Guns" when it was announced said Monday the game has proved a hit, with "Palworld" selling more than five million copies in just three days.

The game released Friday on the online Steam platform blends weapon-wielding player avatars with monsters that look eerily similar to those in Nintendo's wildly popular "Pokemon" franchise.

"Most people, myself included, thought this game was going to be a meme," read a review left on Steam by the account of game developer Pirate Software.

"It's actually insanely detailed, extremely well optimized, and compelling as hell."

One player responded by saying they were "blown away" by the game and contending it has potential to become "legendary."

As of now "Palworld" is in early-access mode and still being developed, with the help of feedback from players, Japan-based PocketPair said in describing its new game.

Palworld has sold more than five million copies since its release on Steam, where it is priced at $27, the company said in a post on X, formerly Twitter.

– Bows and assault rifles –

The game is home to more than 100 different characters — called "Pals" — that players can capture and turn into allies for adventures in the game, according to its creators.

Palworld integrates "elements of battle, monster-capturing, training, and base building," according to the game's description on Steam.

Players can battle with weapons from classic bows and spears to assault rifles and rocket launchers, the description added.

Players have the option of working together in a virtual world setting, working as a team or battling one another, and even stealing items, the game maker explained.

– 'Death threats' –

But some on social media accused PocketPair of copying from Pokemon, posting images of very similar-looking characters and features from the game and the franchise.

"This is a COMPLETE carbon copy," one X user said. "Another copied design, shame on you palworld," commented another.

PocketPair's CEO Takuro Mizobe said the company was "receiving slanderous comments against our artists, and we are seeing tweets that appear to be death threats."

"I would appreciate it if you would refrain from slandering the artists involved in Palworld," he said on X.

Others backed PocketPair.

"Any Pokemon fan angry at this game and demanding it be banned for one reason or another should be blaming Nintendo for missing what has been an untapped market for years now," read another comment on X.

"This is a testament to just how much PC gamers wanted some kind of Pokemon game on PC," the comment continued, referring to personal computers.

Serkan Toto from Tokyo-based consultancy Kantan Games said that the success of the game was an "absolute surprise," including for PocketPair.

"This only happens in gaming every several years," Toto told AFP.

"But would anybody be interested in the game if these characters didn't look like Pokemon? Of course, the answer is most probably no," he added.

gc/mlm/mac/stu/aha

© Agence France-Presse