Nice! For the flip, obviously you wanted the coming down to be that slow; however, I don't think it looks very good that way, to be honest. If you had made it slower earlier, like right before the peak, it might've worked better; but the way it is right now, it kinda looks like you just couldn't get the falling speed right. In terms of making your animation more cartoonish, which I'm gathering is what you're looking for due to the painting test, exaggerate more. As in everything. Make him jump up before painting the wall and slam down on the ground, make him move his legs to try and stay aloft before slipping as well as making the sliding longer, and the like. Cartooney animation is almost entirely achieved by exaggerated movements.

-kcirbfilms
P.S. The animation was of course top-notch, I'm simply assuming that you're going for a more cartoonish feel, and giving you advice based on that. In terms of more serious animation, my only critique is that first falling movement.