hedwards: But, making sure that they've at least bought the game goes a long ways towards clearing up the cruft of people reviewing games they've played years ago, but don't like enough to buy again.
If the game they played 15 years ago was really that good, then buying it now shouldn't represent a problem. Most of them are rather cheap anyways.
Breja: Unless THEY ALREADY OWN IT. Just not on GOG. I happen to own quite a few old-ish games on DVD, they work perfectly fine, and I see no reason to buy it a second time, cheap or not.
Also, you do realise that there is a lot of new games on GOG? That can be bought in plenty other stores, digital or not? I already mentiond this before. Sometimes GOG gets new games a bit late. If someone got it elsewhere first, suddenly they won't be able to review it here, unless they buy it a second time. All to remove "nostalgia factor" for the old games (which will not really work anyway). This is ridiculous.
You're supposed to be reviewing the product they have for sale. There's any number of other places where you can go if you just want to write a generic review about this particular game.
And yes, there are a lot of new games, I'm not exactly sure what that has to do with the fact that the reviews of games here is about reviewing this product. In most cases the games should play the same, but they might not always play the same due to reasons.
Christ, are you people really this dense. Reviews of games here are of the games they're offering for sale, not random other versions that are available in various other places. Patches here when provided tend to take longer, as an example, so a review of a current Steam copy may not be entirely valid for a copy that's sold here.
timppu: Meh, I want to see both kind of reviews:
1. People telling how good the game itself is, regardless of from which store they bought it.
2. For possible GOG-specific technical issues, yes I want feedback also from people who have played the GOG version.
The problem with #2 is that some early "technical reviews" might have been fixed already by the time I read it. So maybe I'd rather have these "technical reviews" on the game sub-forum, not in the review section of the gamecard. At least in the game subforum it is usually mentioned in the same thread if the technical issue is already fixed.
As Breja pointed out, GOG is not only about old games. To me it seems OP was mainly talking about the old classics (with possible compatibility issues) with his suggestion. I'm not expecting to see many GOG-only issues with newer games.
It's more common with newer games than older ones due to the patching that goes on. Don't get me wrong, I support GOG in being a bit more thorough about verifying patches, but it does mean that copies bought elsewhere may not be exactly identical at any given time to ones purchased here.
At the end of the day, the reviews are supposed to be of games bought here. Not generic reviews of the game. If you want to write those, there's any number of places where you can do just that. But, if you're not reviewing a copy that was bought here, you shouldn't be posting it here.