dtgreene: Except that such games are likely just the original games running under emulators that happen to support this feature.
It's not the case for the new Turrican versions.
Really ... you don't need to tell me about emulators. I worked with these for literally decades now.
Of course part of the software runs emulated (heck, even the Amiga version of Turrican 2 uses code that was created to run an Amiga emulation on a Atari ST, that's how the 7 voice system was created), but it's not just a 1:1 copy.
In some of these you can select different versions of the soundtrack. They also added til trials (which I am not interested in) and such stuff.
I still have to try it, but they promised a Turrican 3 version with the graphics from the Megadrive version and the music from the Amiga (it's just too bad they didn't include the excellent Turrican 2 DOS version, since that was done by someone else).
And what about the XBLA Version of Prince of Persia? It's not available on any other system
https://www.youtube.com/watch?v=Dvzg_RSXKfg I think, also Gyruss was remade and was not run in an emulator
https://www.youtube.com/watch?v=nm6MS6iQlsU Same games, but with enhanced graphics.
But let's just assume for a moment that you are right ... they still don't sell it on PC, no matter the technological background. So as long as one doesn't want to pirate these games, there is no option to play them on PC.