alt Hacker NewsThere are some games on GOG that still include DRM. The one I can remember offhand is Cult of the Lamb where the game would only run until a certain milestone at which the copy protection determined the GOG version was pirated and would gate the player from advancing. There were forum posts from the developer confirming this was intended.
I'm honestly pretty disappointed that GOG is still selling the game. If they are going to sell it at all they should have massive warnings all over the page that the game is broken. https://www.gog.com/en/game/cult_of_the_lamb