Olauron: Steam reviews are not a good measure of quality for small games that are not bought by everyone and their dog, because only owners can publish reviews.
Pheace: Wait, how is that a bad thing? That sounds like a positive to me.
You need to remember that you can get a refund on Steam if you play less than two hours. It can therefore be assumed that those who absolutely hate the game will choose to get a refund, don't have it in their collection, and don't end up writing reviews about it. But those who like the game and have it in their collection, can review and rate it, so the whole system automatically favours positive views.
Having said all that, GOG too should have the policy of allowing only verified owners of a game to post reviews about it. As GOG doesn't have such a crazy refund system, those who are disappointed with their verified purchase would more likely end up writing about all that, therefore the reviews would overall be more neutral.
Anyway, that all aside, GOG should have some public and open guidelines about their inclusion/exclusion policy with games. Although quality is subjective, there have been cases where it really hasn't been the lack of quality, at least when compared with other games in the same genre, that has been the problem that lead to GOG turning the game down.
