Looks like publications that review games play fast and loose with the ethical standards espoused (if not embodied) by most journalists. ArsTechnica explains how game companies manipulate their press coverage:

While gaming may look like a huge, scary industry from the outside, it can be a surprisingly cozy place once you know that world a bit. It’s easy to make enemies, and since public relations staffers change on an almost monthly basis, you never know who is holding a grudge at what company. If you anger one publisher or the wrong PR person, you could find yourself out of luck for information, interviews, or even invitations to trade shows for a long time to come. For sites that need fresh, exclusive news to function, it’s the kiss of death. Even without lording advertising dollars over your head, they know how to hurt you.

Of course, publishers also want to help you. Microsoft doesn’t send people gigantic bags filled with systems, games, and hardware because they really like you. They want to get products reviewed, and they’d also like you to think of Microsoft as the cool company that gives you free stuff. One gaming company even sent a few members of the gaming press onto a zero-g flight to promote its game. The trip would have cost thousands of dollars if purchased, and one writer who went gushed about how the gaming company made his dreams come true. Again, it’s not paying for a review or positive coverage, it’s just a very expensive gift. When you hear writers say things like “they cannot thank so-and-so enough” for a gift like that, you know it’s a lie. There is a very specific way to thank them. That is why the money was spent.