Just tested on my side and the application crashes outright with the message "game.exe has stopped working". Windows 8.
This happens with or without fullscreen requests.
Kind of a pity, really - the browser object seems to work pretty well with some functions (vibration and fullscreen) but not at all with others.
@Ashley, is there any chance we could get a node-webkit object with support for fullscreen and closing, now that it's part of the stable releases?