Unity also isn’t used just for games. It’s a way to build cross platform apps with some level of 3D graphics, game-like interactivity, or navigation.
A couple years ago I spent a bunch of time reverse engineering a very expensive robotic cat toy after the company that made it went out of business and delisted their companion app. (Effectively rendering it useless.) When I started trying to crack open the mobile app to understand more about its data structures and such, I was very surprised to discover it was actually Unity based.
It wasn’t really a game, but it used game-like navigation through its menus and utilized controller-like assets to interact with the device. On the upside, this also made it much easier to reverse engineer as there’s a ton of tools that specialize in extracting Unity assets and decompiling the .NET code to something more readable. I wasn’t interested in hacking the existing app so much as I was trying to understand its workings so I could create my own.
Between that, a ton of BLE sniffing, and reverse engineering the device firmware with Ghidra, I was able to create a few things that worked reasonably well. A mobile app, a MacOS app, and a standalone hardware device to control it without even needing a mobile phone by using an ESP32 and I2C-based controller. I gave up on the project when the original software showed up again in the App Store. But, it was a really cool learning experience.
