Technically the graphics aren't 8-bit, because they're in black and white, but I'll let that slide because this looks REALLY professional!
Upon playing though, I realised a few things. The camera is EXTREMELY rigid, and doesn't lend itself to platforming OR shooting particularly well, and also the sound is a bit iffy. I know sfxr is good for making your own free sounds, but the gameboy never had a sine wave available, or MIDI instruments, so the whole "8-bit" aesthetic is kind-of ruined by those things.
All in all, though, this is a fun romp if you're up for some quick, halloween action.