A game which maintains a high level of engagement during that review period but which drops off not long after that could show this kind of discrepancy between customers and reviewers. I don't want to suggest that Blue Prince is this sort of game (never mind that it might be deliberate) but I think it's possible for some games to have been designed for game reviewers rather than for long-term players. The top HN comment on this story (as I write this) would seem to indicate that the game has an issue with running out of steam after a few hours.
This sort of thing is not unheard of in other media as well. In the film industry this strategy is called Oscar-bait. Of course for a film it's not based on duration but subject matter. Certain themes and filmmaking techniques have been accused of being targeted at the narrower interests of the Academy rather than a broad audience.
I'm not exactly sure what leads to such a dramatic disconnect. Maybe game reviewers just value different things than the general population.