Better late than never. Sorry I hadn't gotten around to it. I tagged a fall onto the end because I got bored, although I dunno if it came out ok.
Edit: now that I can see it in full (I couldn't before scaling down) I think I need to double the number of frames in the fall. I might at some point. Anyway, that's the run you wanted.
Your run is okay, I don't think you put enough time into it.
First off, the arms need to be raised higher. It looks like you're going for a springy, cartoony feel in your animations. You need to exaggerate on the arms a bit more. I like the hoppity-hoppiness of your legs (it was the only term that came to mind) but I think that while in mid-air, he should be raised higher off the ground. When his foot is on the ground I think his legs should bend more, which involves keeping him on the ground for a little longer. This creates the effect of a quick, jump style run which I think you were aiming for.
The slip and fall, as you'll probably agree, doesn't look too great. That's okay though as you clearly got bored of running and wanted to make it more interesting. We all get bored of running and walking in our animations, it's easy to make your stickfigure run but it takes time to animate a run
well. The tumble firstly shouldn't start with the guy falling backwards, from what I can see. If he was supposed to slip over backwards then make it more obvious. It looks as if you're going for like a cartoon-style tumble, where the character stays in a position for a short amount of time and then quickly changes. You need to keep the character in one position until they hit the floor, where you should quickly change the character into another position and so on. The positionings in the tumble were good, however the speed is too fast to fit in with the steady pace of the run. You need more air-time and pretty much the same floor-time to improve the tumble.
Sorry if it sounds a little... cryptic, I was typing as I was thinking. Hope it helps. Tell me if you want another CC on a particular message, and if you don't understand any of the above (some of the stuff sounds a bit odd) then ask.