Fullscreen is on now, there is a button in the bottom right corner of the frame. I had simply left the option off, thanks for pointing at it.
The lag on upgrades was a real bug: every purchase redrew the whole nest even when nothing about it had changed. Fixed in the build that just went up, along with saving, which did not exist at all before.
The lack of progress is the note I cannot fix in a day and the one I will be thinking about. If you have a minute, what were you expecting to see change that did not?