Cartridges really have stood the test of time, haven't they.
They're certainly great to have around the house, not just as a collector's item or for nostalgia, but because you can also turn them into homebrew retro consoles.
And according to Howchoo on YouTube, it's pretty easy. You'll need a Raspberry Pi Zero — it's got to fit inside a retro cartridge, after all — as well as the following:
1x Raspberry Pi Zero plus power supply 1x USB gamepad (2x if you want to play with a friend) 1x 32GB MicroSD card 1x Mini HDMI male to female cable 1x 4-port USB mini-hub 1x Micro-USB male to female extension cable 1x Micro-USB male to USB female cable 1x Glue gun 1x Box cutter 1x NES Cartrdige 1x roll foam tape 1x glue gun sticks
You'll notice that no soldering is required, which makes this project infinitely easier. But if you'd like to see how it's all put together, there's a handy video below.
If you want more advice on how to put this together, there's a written guide at HowChoo that includes advice on installing RetroPie, widening the cartridge, and other bits and pieces to neaten up the whole thing.