If you’re interested in retro gaming, the easiest and most affordable way to build a dedicated gaming rig is to get a Raspberry Pi and flash the RetroPie SD card image. It’s quick and easy to do, and even a Raspberry Pi Zero W can run games from the 8-bit era or earlier flawlessly. Once that’s setup, you’re going to want an enclosure to protect your Raspberry Pi, and Howchoo has a great guide on how to make one from an old NES cartridge.
To follow this guide, you’ll need a Raspberry Pi Zero W, a cheap Amazon Basics USB hub, a couple of very short cables, and some kind of NES cartridge. It’s best to use a junk game that nobody actually wants, because it’ll be less expensive and no one will attack you for destroying a game that’s actually good. You’ll start by taking apart the cartridge case, which you’ll need a special screwdriver to do. If you don’t have that screwdriver, Howchoo walks you through how you can make one out of a toothbrush.
The next step is to pull the actual circuit board out of the USB hub. It’ll fit perfectly into the NES cartridge, and can be simply hot-glued in place. Then route your USB and HDMI cables. At this point, you’ll want to go ahead and flash your SD card with the RetroPie image and go through the setup. The Raspberry Pi can then be mounted inside the cartridge with some double-sided foam tape. Then just screw the cartridge back together, and you’re done. The ports are all exposed and accessible via the extension cables, and you’ll have cool enclosure for your RetroPie gaming rig!