I did a trial run with several demos and the most of them was working. Sometimes, the blitter bug showed up, causing garbage on the screen (partial or complete), but even at these conditions, the music was still playing without errors. A simple estimation would give about 10% total failure rate (crashes, lock-ups).
Failing games - haven't tested all of them I have and I can't remember all of those I had tried. But as ususal, the version of Obliterator I have does not work (it fails in WinUAE too). Outrun did not work either.