Hi Schnippshly,
A (slighlty outdated) list of games that are supported in stereospic 3D can be found here: http://www.vorpx.com/games
To your second question: Unfortunately for almost all games some individual adjustments have to be made to make them in work in stereoscopic 3D, that’s why unsupported games ‘only’ work without stereoscopy.
Non-stereoscopic games are still a very immersive experience with vorpX BTW, since everything else (including full head tracking) works in most cases. To check how immersive the world still is without Stereo-3D, you can make a simple experiment: close one eye and see whether you are still immersed in the world. :)