Well looking at the way the game loads and the fact that it's only 26 kb on this site that means the actual game is loaded from a different site. So it could be possible that that site was down or was having issues when you tried to play it.
Right now it works for me. Even though the initial load indicator was stuck at 0% the text underneath the loader changed and after a while the game started itself so I guess the loading worked.
So it could be either that the site hosting the actual game file was down when you tried or it could be that that site is being blocked by your school.
"The absence of rules is the enemy of art." ~Orson Wells
