Added a toggle button for Windowed and Fullscreen today, and made it actually work. I also did some tweaking of the icons around the edge of the screen (pushed them higher, made the outlines more consistent).
One of these days I need to align the outside UI stuffs to the edge of the screen
The About/Credits screen icon is now a speech bubble (was a “?”, so not to confuse it with the help menu). Just a few more tweaks to go before I dive in to Android.