Resizing. My students have a wide range of different machines, and then also a wide range of different screens and resolutions. A large part of them had problems making the whole game fit on the screen. The solution ended up being to use the game in a window, and scroll up and down if it was needed. The fullscreen option was not working as intended, since it was simply removing and browser-background and keeping the resolution of the game at the same levels.
Reported on 1.0