I don't know what this is trying to be. I kinda feel like your target audience is either 1. just your friends, or 2. people who are already pretty familiar with this series and the concept. I'm neither of these people so I just felt alienated, not understanding who any of these characters are (they really aren't distinguished well except for Rat seeing as he's the focus). Pretty much none of the jokes worked for me either; this whole cartoon seems like a way to publicise the injokes you have with your friends or something, and it doesn't work. In fact, a high school comedy setting where the author inserts himself into the cartoon with his friends just seems like the most unoriginal thing ever, man.
But it could've been saved if it had good character designs, drawings or animation. The only differences between the characters are their hair and clothes, they're otherwise all the exact same template. Size, head shape, facial features (especially since you've emitted most of them). I mean god damn, even the shots outside the school where you just copy and paste the same grey character walking past the scene 3 times. It's just lazy.
But the biggest problem throughout all of this was the sound design. The voices were all bad quality and quiet as hell, or would suddenly turn really loud. And it's pretty frustrating that I had to mute this computer to stop the music on the menu screen while I write this review. I guess that's not something I should mark you down for, but you should consider stuff like this in future.
The ending made me kinda almost smirk, I'll give you that. But you need to either make this a lot funnier or a lot better animated and drawn (preferably both, though).