Metacritic rated Pokémon Pokopia the highest-rated Pokémon game on its site.
The game received generally favorable reviews from critics, and its Metacritic reception placed it above other Pokémon games listed by that aggregator. Reviewers often highlighted its combination of building, exploration, Pokémon relationships, and attractive environmental design.
Pokopia also performed strongly on another review site: OpenCritic reported that 98% of critics recommended it. These are separate aggregation services, so OpenCritic and Metacritic should not be treated as interchangeable answers.
Individual publications gave their own scores as well. Famitsu’s four reviewers awarded a combined 39 out of 40, while GameSpot gave the game 9 out of 10. The question asks for the named aggregator associated with the highest Pokémon ranking, not an individual publication.