Review guides that arrive with a pre-release game aren't terribly uncommon. There's no guarantee who will end up with the packet at most places, and there's an attempt on the part of the publisher to inoculate itself from worst-case scenarios by including a picture of the game controller with every function mapped to it. They want to make sure the reviewer picks up the right thing, and doesn't attempt to play their game with a stapler or a snowglobe.
Some guides include language that mirrors the ongoing campaign that you have heard elsewhere - you might pick up snips of the overall themes they're pushing. They might emphasize certain kinds of interactions, whatever they're discerned their "key differentiators" are. Sometimes the disc just appears in an orange envelope with a sticky note on it, as if to say, "Forgive us. We did the best we could." You can't really hold to that, though. That's what Odin Sphere looked like when it arrived, and Odin Sphere got its fucking hooks into us. You can plant a sheep plant in that game, and grow sheep. I don't know what else you could possibly want.
The most rare kind of letter that accompanies these things is the direct entreaty. I don't have a review copy of Fable II, and it comes out in ten days, so who cares. But to hear Variety's Ben Fritz tell it, such an entreaty arrived with his copy: to let a non-gamer play the game. There are challenges there, conceptually, which we investigate in our customary fashion. At the top level, a focus on new markets is clearly a growing force at Microsoft, which would make it a focus for its wholly owned subsidiaries. But beyond that, the entreaty presents an interesting idea: that reviewers don't have the intellectual tools to fully perceive the medium.
We've presented the same point ourselves, in different ways, but the job of the reviewer is impossible - something else I've taken pains to make clear. The fact they they're bound editorially to measure a game's amusement in cubic centimeters (or whatever) is only one problem. We want them to be both useful and impartial, and when they don't manage this apex of zen bullshit they've committed some kind of eternal crime. It's no wonder they leave their posts as journalists to join the industry proper. If they're going to do an impossible job, they'd prefer to be paid for it.
There was (yet another) fascinating article over at Lost Garden awhile ago dealing with something the author calls "Expertise Bias," which he probably explains better than I could. But if Fun is generated by learning new skills, and you've been playing games for decades, it's fair to consider the effect. You can look at these things in terms of a calcified critical perspective, and it makes for incredible rhetoric. The medium has changed substantially on their watch, though - irrevocably so. New people are making, playing, and thinking about games. It takes time to calibrate your instruments.