It's a puzzle-solving game in which you're tasked with repairing various gadgets and items, with a story running through the entire thing. You'll need to disassemble each object, figure out what's not working, fix it and piece it all back together. The items are typically less complex than their real-life counterparts, but that doesn't mean it's not enjoyable or satisfying to repair them.
Apple Arcade games aren't available elsewhere on mobile (i.e. Android or the App Store) or any other subscription service. Consoles and PC are fair game, though. Several other titles are out on or coming to consoles or PC, including What The Golf?, Sayonara Wild Hearts and Shantae and the Seven Sirens. Apple Arcade is still great value, but it's good that some of its best games are available elsewhere too.