Here are a few games I didn't manage to get working with the current core (PAL, kick1.3, 512Kb or 1Mb of chip, no fast). It may be due to the ADF versions (but I usually tried several for each game).
- Mega Typhoon : black screen
- Captain Blood : guru meditation
- Lionheart : white screen (or black, not sure

- Wizkid 2 : empty menu, can't start the game ?
- Wiz'n'Liz : black screen
- Metal Masters : controls issue (not the right directions triggered)
Edit : actually works with English versions of the game (tried French initially - Maupiti Island : never got to the title screen. The Minimig LED keeps on flickering (but not the keyboard LED)
- Jim Power : works but parallax scrollings flicker on the shoot them up level (after the first boss)
Edit : works with a different version - Worms (Fairlight version) : black screen
- Kid Chaos : some tokens/bonuses tend to flicker a bit when scrolling quickly, but this may be a normal behaviour. The scrollings are perfect and the game 100% playable.
Apart from that, most games work perfectly. Demos generally work with minor gfx bugs.
Thanks for reading this

Edit : oh, also, the competition pro pad behaves really strangely. (depending on the game)