AlexKVideos1: How many votes are typically needed for a game to get in the running?
There is no typical amount. If GOG can fairly cheaply get the distribution rights to a bunch of games at once from a single publisher (even titles with very few votes), and they don't have to do too much to get a DRM-free build of the game running reliably on recent Windows systems, then even somewhat obscure games can show up here.
Conversely, even wishes with thousands of votes mean nothing if the rights owners (code/assets, IP, publishing, what-have-you) are unwilling or unable to cooperate -- either with a potential distributor (such as GOG), or with each other (in the case of fractured rights).
But anything with a vote total lower than triple digits shouldn't be expected here real soon.... ;)