The jumps were nice enough, the way the skateboard is made when it rotates during the tricks is good, but the stick and the skateboard lack of flow and easing when it does those trick, you should ease more and make smooth the Skateboard and the stick during the tricks (don't double frame too much, or it will be choppy), also, use a v-cam in a good way next time you animate, it's kinda awkward to watch, also, the background is pretty basic, anyway, remember, pratice help everyone.

thanks for your help, i'm gonna take this in count next time :D

Oh also instead of making the stick freeze and the background move every time he goes off-screen (it gets kind of annoying) you can use something called V-Cam.
Link here: http://www.mediafire.com/?x5i44ncys60efrl (credits to Hyun)
Just move and resize the box around. It's like your video camera. Whatever is inside the box will be onscreen.