Ok well it's really hard to CC if the animations are all half a second long I think I can do the first one.
I'ts way too fast to catch whats going on first just make a stance then when you have to punch you need anticipation not just have your arm hanging the punch it has to be back then wait a little then quick movement when he thrusts his arm and punches him. I think you could do better they must have takes you like 1 minute put more time into your animation and you'll be alot better.
Here is one i just made, My brother messed me up, and microsoft was about to shut easytoon down again. so here it is, a epic kick fail, with a hands free stickman.
Ok like I said before you need anticipation you dont bend you legs a centimeter then jump right.
Also I think he is jump then pushing his foot of the the falling block(that dissapears). It needs easing make it smoother when he falls too.
It's alright. You still need to learn the basics, your particles are weird, the explosion thing was okay though. I suggest you start practicing on punches, kicks, walking.. stuff like that before you do effects.