Can you do this? My game looks excellent in crop-mode and full-screen and I've done the calculations to allow the screen to change size, but it runs very poorly on older hardware and needs to be run in a smaller screen-size, set at 800x600, which requires me to change the 'Fullscreen in browser' mode, with an option in the game or something. Can you change that setting during run-time?
I know I can change from windowed to full-screen with the browser object, but I don't see a way to change the project properties.