The big problem is that with newer Amigas (like the 1200), you can switch between PAL/NTSC in the early boot menu, but the switch is "forgotten" if you're booting a game with a non-dos boot sector. If you have an NTSC machine, you'll have to use a boot loader like Degrader to change the system mode...
...or just use WinUAE for running old games.
