Before the Game Boy came along, handheld gaming consoles were limited to just a single title, played on a low-quality segmented LCD display. At the time it was cutting edge stuff, but by today's standards they kind of suck. So to scratch his nostalgic gaming itch, Instructables contributor Andrew Hannay built his own Game & Watch with improved electronics so it could be loaded with multiple games.
The controls and actual gameplay on Hannay's creation—cobbled together from an old handheld, a Nokia cellphone display, and a PIC18F4550 controller board—are still crude and rudimentary compared to what modern hardware like the Nintendo 3DS is capable of. But it works and plays just like the handheld games he grew up with.
And now there's the added bonus that Hannay's Game & Watch can be loaded with all of those classic games at once, so he doesn't have to fill his pockets with multiple handhelds. [Instructables via Technabob]