kero42: Here is the reply from GOG Customer support, received yesterday. I believe there must be a misunderstanding somewhere...
I'm afraid that it is not possible to rate a game by assigning it a number of stars only. You would have to add a written review as well.
In order to do that, select a number of stars, click "Add your review" below, write the review and its title and confirm with "Save my review" :)
Cavalary: What the... When did that change? Talk about a call for pointless reviews.
But the thing is that existing ratings WITH reviews aren't visible either.
Yes, I had similar thoughts, this seemed so silly that I was almost certain there must be a misunderstanding.
I wrote to support once more, and they agreed that rating a game without writing a review should indeed be possible. They couldn't give me an ETA for the fix, however, so let's wait and see.
