To be fair, 7 critics have reviewed Runbow so far, and I highly doubt too many more will. That's one of the major issues for using metacritic as a metric for... well anything involving indie games. It's far more likely for 7 people to have similar opinions than several dozen.
As for my response to OP, Mario Maker wins. Star Fox 64 is the only Star Fox to exceed 85, and I doubt Zero will, especially with a supposed runtime equal to that of a movie. The original Chronicles just barely topped 90, and some previews for X haven't been super favorable. Fatal Frame, A) exceedingly niche horror franchise and B) no game in the series has topped 84. As for Runbow, one review below 80 will knock it below Mario Maker. Is it possible for Zero, Chronicles X, Fatal Frame, or Runbow to win? Sure, strange things happen, but I doubt it. I think Chronicles has the greatest chance.







