I hope he doesn't lose his grip, or it's certain doom. I like the cartoony feel of this sketch. I found that adding a tiny bit of narrative does indeed help me complete a sketch.
There are some anatomy issues going on around the shoulders. While there is nothing wrong with being abstract, you first have to know the rules before you can break them. Repetition will correct a lot of those issues. Or I could just fix it in Photoshop.