Projects like eXoDOS and DOSBox (and its derivatives) have basically allowed most of DOS and win31 games to be in a very playable state. GoG is doing the detective work of finding out who owns it and trying to monetize parts of it as well as fixing some of their own stuff. When it comes to many of the late 90s win9x/winxp games those are in the territory of 'maybe runs'. Due to the way windows is subtly changing the API and what a standard windows install comes with. Also APIs that now return even more stuff than what they tested with. Such as a video caps function may now return 500 items when it was tested to run with 60 and the input buffer maxes at 256. Never mind many of them act totally bugged out if you hand it a 4k screen and you have scaling turned on.

Had one game from a few weeks ago that I could not get to run. Turns out it was an intel video driver bug. Really old intel driver worked. One from 2 years ago didnt. One from a few weeks ago did. Old nvidia worked, newer ones broken. One windows box worked the other didnt. Shims like dgVoodoo2 and dxwrapper help to a point But still have lots of issues. Then on top of that if there is a online component the game will at best hang/timeout at worse crash out. Have one game if I open the leaderboard on it will crash the game. The board was apparently turned off 15 years ago.