Well, if I were to explore compatibility by testing a few titles and looking for anomalies, what would be the best games to test across emulators to determine accuracy, and what things should I be looking for?
Fighting Run, for using the 4-colour sprite mode of the PCE in-game. Perhaps some PCE emulators don't emulate that.
TV Sports Basketball,
Art of Fighting ACD, for having high-res modes and switching resolutions mid-frame, respectively.
Jinmu Denshou, for changing the screen height on the title screen, causing some dumb emus to resize their windows non-stop in windowed mode.
Yo! Bro, for having a nice, wide screen that some emulators may cut off.
Any others?