Zeroth point: No preloader or replay button. That hurts no matter what your submission is. Look into it please. Either that or make it a video file with Swivel.
First point: When you submit something to Newgrounds, it should probably be longer than 4 seconds.
Second point: Is William a slug with a head or did you forget to draw the rest of him?
My two cents: I like your drawing style. Make it longer and you will have a winner. This sort of thing also seems like it would make a great children's story, that seems to be the angle you are going for with the art style and the one line you have in it. It would be nice to see something akin to Winnie the Pooh, where William Garfield gets involved in light-hearted adventures and we get to see his friends.
Also, is he supposed to be reminiscent of U.S. President James Garfield?