That was pretty neat! I sadly couldn't pick up the golden key in between the barrels, it kept focusing the book instead.
I also agree that the default window is very small, but (depending on browser) you can shift-rightclick the game frame once it's loaded and then only show this frame to have a somewhat fullscreen experience. Would be better to add a fullscreen button to your page, but this workaround is for those that want to play in the mean time.