I found your problem, your on a mac. They are not designed to run any games.
gth ok,
also i have encountered another problem, you know how the cursor doesn't go out the blockland window. well, it seems like it does but its invisible. example is, when i click something in blockland, something outside of the window will get highlighted.
or if i have a window open behind the blockland window, and i click on something on blockland, the window will act like it has been clicked on
does anyone know how to stop this