GB Studio lets users create 2D mini-games without any programming, thanks to an Electron application. You can design your graphics in any editor that creates PNG files, and music comes courtesy of GBT Player. When you're done, you simply export as a ROM file that can be played on Windows, Mac and Linux. You can build a HTML5 version that works on mobile, and if you have a USB cart, you could even play your games on that now 30-year-old Game Boy you've hung onto since the 90s.