They seem to have stolen several 3D models from Pokémon. Like, not designs "inspired" by Pokémon. Actual 1:1 stolen models.

I was curious too so I ran it through kagi’s ai summarizer. tl;dr copyright infringement on Pokémon.

• Pokémon World (Po World) has sold over 5 million units in just 3 days, with the majority of sales on Steam despite being available on Game Pass.
• The game draws comparisons to Pokémon but also incorporates survival and building elements like Ark. Players can capture and train monsters.
• There is debate around whether AI was used to generate monster designs, though no conclusive evidence either way.
• Many monster designs closely resemble Pokémon, potentially infringing on copyright. Some models appear nearly identical to Pokémon models.
• The game's success puts pressure on Game Freak to improve the quality of the main Pokémon games.
• Genshin Impact faced similar initial accusations of copying Breath of the Wild but has become its own game over time.
• Nintendo may pursue legal action over copyright infringement depending on their view of the monster/model similarities.
• The developer claims all necessary legal hurdles were passed but no action has been taken yet.
• If the main Pokémon games provided what fans wanted, Po World may not have gained as much success.
• The video discusses both praise for Po World's gameplay as well as criticisms of its similarities to Pokémon.