From Richard Bannister:
Handy supports reasonably good compatibility with Atari Lynx ROMs. There are a few titles which don't work, but the majority seem to work pretty well. Handy also supports full sound emulation. For those into useless trivia, Handy was the first emulator on the Macintosh to support loading compressed ROM images - an idea which has since been adopted by many of the other emulators out there.