If only the writing were better
It's really a shame, the animation and sound is great and the characters are okay in design, but the writing... It's just so... predictable and lame. I know that in projects like these the writer is "god" but all of the jokes feel like you're hearing the writer DESCRIBE the joke, rather than actually having the characters drive the plot.
I just get sad to see so much good work being put making such a bland script a realization. He cuts off the dogs leg but it doesn't do anything? They sit and scream in horror and the dog just keeps bleeding. The dog gets the tiniest sip of alcohol and instantly bolts like lightning... You're trying too hard to constantly go against expectations -- that's not all that humor is. Even Monty Python knew that you had to make the audience feel like everything was normal before you did something totally wacky. The key to "left-field" humor is the fact that everything else is normal. Once EVERYTHING is left field, there is no more left field, you know?
Also, lots of the jokes run on too long for their own good. The "Schme" scene was SO predictable from so far away, by the time you get to the actual "punchline" it's lost all of its steam. One of the best things I can suggest is that you have multiple factors going on at the same time -- this keeps people's attention split so that the scene is more lively.
Have multiple conversations intersecting, or simply cut between different scenes. For example, if you had intercut the villain dialogue scene with the hero dialogue scene, you would right away feel a more upbeat pace and feel like there was a bigger picture forming.
Anyway, there's all sorts of advice, but basically the writing is too masturbatory and self-indulgent.