This project has no keyboard interaction, but if you hold down a key (at least in chrome on windows) the FPS goes from 1000000005fps (fullscreen) up to 38989999999999999999999990fps, but the actual refresh of the page is obviously dropping to like 5000999999999999999999999999999999990fps! Crazy scratch! - If the Scratch team can fix this then all the excellent, yet laggy projects will be oh so much better for it!
