“Chad McChad” (not, I suspect, his real name!) has done an absolutely awesome job creating a retro gaming machine out of an old GameBoy and plenty of other parts, as well as a core of a Raspberry Pi Zero. This is one of the best jobs I’ve ever seen – by using the Zero he has been able to cram a lot more electronics into the case and, with some careful Dremmelling and hand-crafting, he has managed to maintain the look of the original console.
Take a look at his build photos and rough ‘how-to’ here. You can see him playing it in the (long) video below: