I loved this so much, I really did. It was funny, the right length (not too long or too short) and I love your style. The only teeny suggestion I have is maybe editing some sound effects when something falls (Doug's head, the detention teacher guy leaping behind his desk [no sound affect for him falling :(] and when Alex falls on top of Doug. I know there's a spine-crack noise but the noise from his body falling is not there.
It's sort of nitpicking, but only because every other aspect was perfect. Keep up the great work!! Maybe make a sequel? ^_^