I would like to know where the game's data, such as the world save files, is stored. I know that on Windows it is at C:/Users/USERNAME/AppData/LocalLow/Denki, but I don't know the Mac equivalent.
Sorry. Missed the "Library". (Users/YourUserName/Library/Application Support/unity.Denki.Autonauts)
The folder may be hidden by the system. Here is another way to get there...
In the OS X Finder click on "Go/Go To Folder..." in the menubar (Command Shift G shortcut)
Type in ~/Library (Tilda forward slash Library) - Then click the "Go" button.
From there Go to Application Support / unity.Denki.Autonauts