I liked it!
While the lipsynching was off a tad, I loved the way this was animated. I especially loved the expression on Tim's face when he walked in on his parents having sex.
Being a Burton fan myself, I can't wait to see what else you have in store. The only thing I could really say, since you already know about the sound and what not, is that you made Beetlejuice's hair the wrong colour. He's blonde, not red. :)