This is the second time I've seen this today and I have to wonder, are some peoples expectations so high that they think that Odyssey might be one of the best games ever, based off two levels shown at E3 and some videos? Really?

Having played it, I would say it will likely score around 9, unless some big things aren't being shown. I don't normally like doing this, because I think it is unethical, but I'm going to explain it based off what I saw at E3 and how it differs from Zelda.

Super Mario Odyssey was, probably the second best game I played at E3 and had plenty to see/do, but it's more another Mario game than something like Breath of the Wild. Part of what makes BotW so popular is that they took suggests like decreased the hand holding, added all kinds of elements to play around with (flying machines and guiding enemies is a good example of this) and offered a new take on the open world. The ability to pretty much do whatever you want is nice and all the little touches make it all the better.

TL;DR Mario will score well because it's a Mario game, but it won't be amazing, because it's just a Mario game.