F-16 Fighting Falcon doesn't display any graphics past the title screen, as it uses one of the legacy VDP display modes (i.e. not SMS mode 4) none of which are currently implemented.

The SMS VDP Test ROM currently fails multiple tests, namely most of the H-counter tests as well as one sprite collision test (off-screen Y collision).

Sound emulation in general is rather inaccurate, most notably (seemingly) playing at the wrong pitch and being slightly too slow.

Hang-On and various other Master System games freeze the emulated system whenever the Pause button is pressed, with the currently played sound repeating indefinitely, and will not "wake up" when the button is pressed again.

Pop Breaker doesn't react to pressing the Start button on the title screen, regardless of the selected option (1 Player or Link Game).

The Z80 core has all official opcodes implemented, but is still missing various undocumented/illegal ones. As ex. Gunstar Heroes (GG) uses some now-implemented undocumented opcodes, it can be assumed that other games might do this, too, and possibly hit ones not yet implemented.

Girl's Garden shows invalid sprites in the top left corner of the screen, as well as a black heart sprite where a colored heart appears near the end of the title screen animation.

The wavy title screen fade-in in Fantasy Zone Gear exhibits horizontal scrolling issues, with the screen sometimes appearing static, not scrolled for several frames.