If you're worried that Nintendo has cornered the market on making tiny versions of its old
gaming devices, you need not fret. Hardware hacker 'wermy' has been working on an emulator that can fit inside an Altoids tin. Here's how he built it.
Built with a Raspberry Pi Zero W, a USB SoundCard, some Nintendo DS parts, a MicroSD card, and some assorted 3D-printed parts (the complete list is here), the mintyPI is a complex project. It requires a lot of the "measure twice, cut once" principal with no take backs, like mounting the screen onto the Altoids tin with VHB tape. The written instruction list is here.
But the rewards are well-worth the effort, if you want a tiny game system with the power to play more than just Nintendo's games. Not a bad deal for a day or two's work.