Although this can fall into the "Hype" category, for large review source there are a lot of politics that are involved in reviewing a game ... Your paycheck comes (indirectly) from advertisements which are (mostly) for highly hyped games from major publishers; and your readers/viewers are dedicated gamers who tend to have bought into the hype. This tends to result in a lot of games being given a certain score regardless of whether they earned it or not.
Another thing is reviewers who start a game with biases or pre-conceived notions about the game. There will (always) be people who start a review knowing what score they will give a game regardless of the quality of the game but this isn’t (specifically) what I am referring to. A game like Battalion Wars 2 (probably) had many reviewers who went into the game expecting it to be a squad based third person shooter and what they ended up receiving was a Battleground RTS game; if you’re looking at a game and judging it against games it is nothing like you will have difficulty coming up with a fair review for it.
The last thing is the amount of time many reviewers actually play these games for. Most game reviewers will devote a day or two towards playing a game and writing the review which is perfect for a six hour single player game, but when you start having games that are 40 hours long with multiple multiplayer modes they really don’t have time to really judge the game. Some of the most hyped games will get more time devoted to them, but there are so many games being released (in particular during the holiday season) that it is practically impossible for most games to get a decent amount of time spent on them. This isn’t that bad when you’re dealing with a game that is so awful most gamers will give up long before you did, but when you’re giving games near perfect scores and only played 25% of the game it is highly likely that the game will be overrated.
