I think it would be optimal if people are able to see that such games exist here and choose if they want to see details about it. The common approach in other marketplaces is to simply display a warning and allow the user to decide if they want to see the screenshots, read the full description, etc.
I agree that there should be indications about the exact nature of the content so there aren't unpleasant surprises. For example, various tags/labels could help in that regard.