HunchBluntley: First of all, not all old games, DOS or otherwise, are classic (there was worthless garbage in the DOS era, too), and not all "retro" games are old (and GOG releases plenty of the new ones). ;)

HunchBluntley: Right, but I wasn't sure if they updated or changed anything for the port. A game being ported to a new platform that long after the original (commercial) version's release is often a sign that some improvements and/or revisions have been made in the process. (Whether the changes are actual improvements is another matter.)

Grargar: "Improved texture and lightmap resolution
Upscaled videos
Added FXAA Anti Aliasing
Added Resolution and graphic quality option
Keyboard & mouse and Gamepad (360/ps4) support and UI adaptation, also added remap feature
Unofficial Wiimote support"

Doesn't look like earth-shattering changes.