I was messing around with key detection, having the intention of making a text editor-like project, and found out that Snap! can detect about every key on the keyboard, even special function keys that only ChromeOS uses.
You can mess around with this quirk by pressing keys with this project loaded. If you're on a Chromebook, try doing the same with the top row keys, it even detects the power button!
Sidenote: I found this works best in the Snap! app that you can install from URL bar while in the editor. I think this only works on Chrome, though.