It's quiet...TOO quiet.
At 660K, there was enough room for some incidental sounds here--the whole thing is horribly silent unless a sound is played. Some forest noise and walking noise (quietly) would greatly increase this, plus where's the hilarious background music? I think most people will score lower cause of the lack of incidental music, even though they won't notice it. I've never seen an I&S short on the Simpsons that didn't have great music!