I like the game a lot.
The game's list of keyboard defaults isn't very long, so in theory, it should be easy to take those defaults, plug them into JoyToKey, and conclude that this game is actually compatible with hundreds of controllers. Unfortunately, trying to understand the Unity input menu is really difficult, because it's hard to tell which rows are irrelevant, and which ones aren't.
I don't know if there's a way to exit the game, besides Alt-F4.