Well done!
Absolutely brilliant. Graphics and style, eight and nine respectively. Eight because some things could have obviously been animated much more fluidly (and I know you have the capability to do that) and style a 9 as always because...well, you do your own thing, and not only do you do your own thing, but you do it very well.
Sound, high points for music, no points for actual sound. I suppose some sound effects are in order, but I guess you don't have a large library of sound effects at this point to add to the movie? We'll have to work on that.
Violence, a seven. There is some violence, not an over the top amount, but just right, and done well.
Humour, 4, as a previous individual mentioned, the teacher as the killer? Heh heh.
Overall, a 9. Keep up the good work.