So I have not played the game, so therefore dont know if its good or bad. However, past experience with "divisive" games like this lead me to believe that the game had a lot of obstacles to overcome to get generally favourable reviews:
1. It is a Sonic-game. There exist a narrative among gamers and gaming-journalists that every 3D Sonic-game is bad, that the "Sonic-cycle" is a real thing, and that Sonic hasnt been relevant for years. This is the story most reviewers went into with when they reviewed decent-to-good games like Sonic and the Secret Rings, Unleashed, Colours, Generations and now this. All games that in my opinion scored in general lower than they deserved. Of course, this narrative wont influence all reviewers, but it will make many of them go into this game thinking "this probably sucks" and make it more likely that they will be looking for flaws rather than enjoying the game.
2. It is made in Japan. There is a narrative especially among gaming journalists that the japanese gaming industry doesnt know how to make good games anymore, that most of the games coming from there are only replicas of their past games, and that many of them are buggy, technically inferior and less innovative. While it is without a doubt true that japanese games sell less in the west than they used to, and therefore are less relevant, I am not convinced that the quality and uniqeness acually have dropped, however if you listen to podcasts or read reviews on the major gaming sites, you will know that the people in the industry definitely hold this view. A game I think got really docked for this was Resident Evil 6, being a huge project coming out of Japan, and while it did have some flaws and was a completely different game than the old RE-games, there is just NO WAY it deserved to score as low as it did on many sites. The narrative that big budget japanese games suck, made it much more easy for many of these guys that would score a mediocre western shooter in the 7's, to score the game a 3 or a 4. With Sonic: Lost World we have another game coming out of Japan, and while a lot of reviewers are of course not letting this narrative affect their focus, it makes many likely to search for flaws that reinforces their view, and also makes it more "acceptable" to give it a low score.
3. It is a thirdparty exclusive on a Nintendo-console. There is no doubt that there is a huge media bias against Nintendo among the general crowd running sites like IGN (you just have to listen to their general gaming podcast to notice this easily). ShockingAlberto wrote once about how he knew reviewers last summer who after having played Rayman Legends - a then upcomming Wii U-exclusive - was already searching for "reasons" why this game was not worth buying and had constructed a "wait for the PS360-version"-narrative even before the game was out. The Wonderful101 in the same way got a ton of complaining in reveiws about being a Wii U-exclusive, and by being that a lot of reviewers felt the need to judge the game in light of how much it needed the Gamepad or not, and even a firstparty game like Pikmin 3 was met with the same criticism. We all know how Zombi U was totally slammed by major sites like IGN, and there are a ton of good thirdparty-games on the Wii that got hit by the same fate (or even just completely ignored by the big sites). With a Wii U-exclusive, a lot of reviewers go into it thinking "why is this on Wii U", and therefore trying to find good reasons in the game for it being on there isntead of on the PS360 or just multiplatform. When they in general dont find this reason (because outside of Zombi U most games on the Wii U doesnt really use the Gamepad in good ways), they will also judge it for that - and the game gets a negative stigma to overcome from even before it is started.
In conclusion, I think everybody slamming this game for all the bad reviews already should think about these points, and TRY THE GAME FOR THEMSELVES. This game might be good, it might be terrible, but already from its inception it had three strong media narratives to overcome, and it is therefore highly likely that this game gets a lower metacritic score than what it deserves - just like games like Wonderful101 and Zombi U did before it.
