In the 15 years or so I've been making games I've found that there are three types of reviewers. That's a gross over simplification of course but I'm a grossly oversimplified kind of guy.
Drive-Byers
The first type of reviewer is the drive-by reviewer. If you're an indie developer, you are more apt to run into this. That's the review that makes you feel like, as you read it, that they were miffed having to take a time out from their first person shooter to play some little indie title's turn based strategy game. We don't get these as much as we used to but we still get them.
These guys scare me because I honestly don't feel like we get a really fair shot. And I'm not saying they give only negative reviews. And that's the worst part. Because if you complain about the review when it was a positive rating you will get "What? We gave you an positive rating?" You can almost hear the "You make a great little shareware type game, I'm sure really hard core nerds get a thrill out of your little game."
But the drive by review can be negative too. If they run into any problem, don't expect a follow-up. These guys also live to put in snarky comments in their reviews -- nothing makes ya look cooler than to practice your written venom at the expense of some hapless developer.
But don't take my word for this. Go over to www.Gamerankings.com some time, think of the best indie games of all time, look at the reviews. Then go and think of some big budget drek that's come out and look at who gave them 90s or higher equivalents.
Casual Reviewers
The second type is the "Eh It looks like it has good production values, seems solid, haven't heard of it, looks good but won't give it better than 4.5/5 because if it was truly outstanding, they wouldn't be a small company." I've said this long before our latest game has come out as I followed the reviews of some truly outstanding and innovative games from small developers get an 80% on the same day they'll put up a 96 for some of the worst shovelware from some mega publisher.
The second type though isn't a drive-by review in that it's obvious they played the game decently. Moreover, these reviews are probably closest to what the overall average will be from both reader reviews and all sites combined. Rather, it's more like there's just a cap. I don't really have an issue with these types of reviews because let's face it, it takes a long time to really review a game and we are a smaller developer. As long as we're not patronized I'm a happy camper.
The text to these reads like this "Great great great great great great." with a 4/5 rating.
I don't get worried as much about the second-type. I know we won't get super high reviews but I know we won't get really low reviews either as long as we've put together a solid title.
The Ultras
But it's the third type that scares me the most. The third type is the hard core reviewer. The person who is going to take your game apart. The ULTRA reviewer.
Ultra reviewers dissect a game to make sure it does what it's supposed to do. They know the genre, they know who plays them. It's not enough to make a polished, solid game. Because they know that many gamers could care less about that. To them, the question is, is the game FUN?
These ultra reviewers scare everyone equally though. Whether you're Microsoft or Stardock, they'll crush you like a bug equally. They're freelancers. Publishers have no power over them. Go ahead, threaten to take your ad dollars away. They'll laugh at you.
They may write for big sites or they may write for small sites. It doesn't matter. Their words carry weight because of years of built up integrity. If they give a big name game a 2 star rating, people take notice. And when they give out 5 star ratings it's equally a big deal. It's not that they give a lot of negative scores, it's that they're immune to hype.