Nice concept, got to say!
I had a few issues though regarding UX and otherwise:
UX First
- clicking on a button to open a menu, then clicking on another button to close that menu and open another one doesn't work; I have to manually close all the windows that I open
- When changing a setting and hitting "Cancel", I still get prompted with the second setting. E.g.: setting frame dimensions, cancelling on width will still open the height prompt.
- Silders are usually more user friendly than a bunch of text boxes
now the other stuff:
- i couldn't export any sprite sheet. Just wouldn't work.
- the trees look a bit flat, i think the branches could use some more rotation