I constantly watch for an inexpensive copy of that Duke 3D Genesis. Actually, that is the only version of Duke Nukem I am aware of, that I don't own. Some day.
Rise of the Triad and DooM are indeed very different, at least in my mind relative to First Person Shooters.
This makes me think of those Wolfenstein secret levels in DooM II? As someone who was greatly inspired by Wolfenstein 3D, that was an over-the-top experience for me finding those in the middle of DooM II!
I would not try to discourage people from trying anything like that... but many ideas which seem "good", only seem that way because they are not thought out.
I would agree that mixing the two, as with many games, might be of interest.
I still would like to have seen a hidden level in DooM 3 be a trip backward into DooM for instance. But immediately, most will realize this "would not fit" as DooM 3 was too "serious" for a break like that... at least compared to DooM and Wolfenstein 3D.
The concept of Retro-Levels would have fit into Duke Nukem Forever I think...
"WTF? Another Time machine... and its activated... and its set to 1995!" The POOF! Back E1M1 of Duke Nukem 3D with another portal that kicks you back at the end... Duke Nukem Forever can't be accused of taking itself too seriously I think.
MrBlackCat