Do I need a new challenge?

It's too late for me to enter this contest (and probably just as well because there's no telling when it'll end) but it's an interesting challenge. I found it via Tim's blog. It turns out he took up the challenge and you can see how he's doing here. I had no idea he was interested in cartooning.

I've already challenged myself with the CliparToons, however I'm not sure it's worth continuing. Should I shift to something else? Any opinions?