Arch-Angel is right, theres no need to insult him, thats the truth about your animation, it looks like a retard running, but I really like that, the animation seems solid, you just have to focus on two BIG things that make your animation look not good, well, its okay animation, but here are tips that will help you improve your run cycle.
The first one is easing, I dont have to explain it to you because you know what is that, right ? So use it ;) I'd also be glad to see some more frames, some more inbetweens, so it looks cleaner, smoother and more fluid, ok ? :)
And the second thing is posing, thats why it looks so "retard-like" this is how those people run, lean forward and do short steps, waving their arms around, that just doesnt make sense, if you ever watched the sprinters on some competition they are squashing and stretching as much as they can,
http://www.youtube.com/watch?v=KRZvlQTTCMg
watch that guy and then watch your animation, do you see that huge difference, well, its okay if you wanted it to look like this, but I guess you didnt :)
Heres something I made, I got 22" lcd and I still didnt get used to it, so I made just 4 key frames, but !! you can almost see the speed, the squash and stretch
http://filebox.me/view/fpmq2amux
but, Im still talking about this like you didnt want it to look the way it looks now, considering theres a moon and dark scenery I guess hes running for his life, to save himself or something, he wants to run quickly, he has to be fast enough to espace, so Id definitely go for some faster looking running.
Of course you dont have to agree with me, Im just pointing out my opinion, which is based on my knowledge and my style, you have to decide whether you like my explanation or not :D
Hehe, I always type and type and I hope you guys can see what Im talking about, because I suck at explaining at english :|
edit, the right arm is really awesome, the timing on it is perfect, I like how it kinda drags behind the body especially when hes going down, that was really nicely done.I really like that and I think that the easing is good, but you just have to add more frames to give it more definition, so I KNOW its good :D