These are two videos of Youtuber LOOK MUM NO COMPUTER building, discussing and demonstrating a giant synthesizer he created using a Sega Master System (Genesis in the U.S.). Impressive I suppose, but I beat Altered Beast AND Golden Axe with a Game Genie.

Keep going for the main video, then another with a more in-depth look at the synth.

Source: Geekologie – Guy Build Synthesizer Out Of Sega Master System (Genesis)