Preservation is important too, but that’s not what I was talking about. It’s very concrete things like does Duke Nukem 3D come with the Build editor that was also on the disk. The C&C remaster made very certain to include the installer; they understand what I’m talking about.
Oh OK, I thought this was specifically about game demos (and their inclusion with full version games, or lack of).
Regarding Duke Nukem 3D everything related to the game was included. So no demos of other games, but build.exe (the editor), setup.exe and of course duke3d.exe (since the GOG version uses DOSBox).
(Of course you probably wouldn’t want to use build.exe except out of curiosity: Well known games like DN3D or Doom hove modern, still in development editors (e.g. Mapster32 in this case).
You also might want to use an open source engine replacement which allows new e.g. graphical features but also more interesting stuff like co-op!)
Sadly the Duke Nukem series isn’t available on GOG any more (including Duke Nukem: Manhattan Project; also Duke Nukem Forever never made it there) after some publisher re-released some remastered version or something on Steam (I don’t really know anything about it).
That’s one of many aspects of the experience. I’m talking about nostalgia, which is the thing they’re targeting, not about preservation, though as luck would have it nostalgia would also be better served through more preservation effort. Preservation here mainly just means not deleting.
No, sorry. I’ve just began to dabble in them myself, so I don’t have any advice or tidbits that aren’t already out there.