My personal critical opinions:
Sound: The dialogue was hard to hear because the voices sounded like they'd been recorded in a small room. Try and make sure your dialogue is echo-free by recording it in a space where not so much of the sound will be bounced back - a room with carpets or a mat, a large room, a room with open windows. Including ambient city sound was a good idea.
And what was with the slowed down freaky sounding narration at the start?
Plot: To be honest, you didn't tell much of a story, and I wasn't really entertained or understand it. It seemed like the main point of the film was to laugh at the guy being repeatedly run over, which may appeal to young children but didn't to me.
Credits: The start credits looked really random....I don't know if that's what you were going for but it looks unprofessional. The start and end credits combined went for about 40% of your total film. You really want to avoid doing this, no matter how fun and simple credits are to make.
Sets: were reasonable I guess. Though I could see the edges of the set often.
Animation: was pretty good.

I was hoping for the first ever Big Rigs brickfilm.