your peeps are a little short this might be on the polykarbon site (one of my favorites <3) but make your legs more or less four heads tall and the torso two more. (while you mull this over, bend your legs back and notice how closely your feet come to your butt, then bend forward and see how closely your chin fits your knees. Admit it, it's true)

your characters have plenty of personality it looks like, so just stretch out those proportions (unless you're going for a super deformed style, but if that's the case, you might want to deform them even more!) and clean up your linework mainly.