I could play it alright, but I am on windows. (very nice game ^^ )Maybe try a different browser? I've heard some people have trouble with Visionaire games when using the Safari browser.
Unfortunately no luck with any browser on MacOS :'(
Is it possible that you are zooming in somehow? Either in the browser settings or in the settings of your OS? That might cause the problem.
I wish the problem were that simple. Unfortunately, it does the same thing even in fullscreen.