While I'm able to run games independently by executing ./snes9x rom, running the Snes emulator GUI from the main menu only shows the list of games, but isn't browsable.
Further analysis shows that this problem happens in all ADVMenu related emulators. Basically, once ADVMenu loads, the screen freezes, though the raspberry pi itself is still functional (can click CTRL+ALT+DEL to restart, for an instance).