All* buttons in menus and screens can now be used with a keyboard (and/or a mouse). This is great for players who have trouble using a mouse and just in general since gameplay doesn't use the mouse (yet). I was previously using browser buttons that could be navigated using the Tab key (or your mouse). However, I had little control over their text size and they appeared tiny on Apple computers.
*...Except some buttons for changing your gamepad controls. I want to revisit how I implemented this system.