The Arduboy is an open-source, credit-card-sized handheld built on the Arduino platform. It’s all about that 8-bit era feel—roughly, you know, a step above those black-and-white LCD Tetris handhelds. The project actually started as a way to promote Arduino, something Arduino fans cooked up themselves. It later hit Kickstarter, became a proper product, and turned into a geek toy. As more people bought it, they did a bunch of collabs and even put out an enhanced Arduboy FX with more preloaded games and USB-C link play… It looks commercial, but the thing is fundamentally open source. You can buy an ATmega32u4 chip and, by mooching off companies like JLC, solder one together yourself. No need to buy the official version—especially since the official one has been out of stock and getting pricier lately.