I believe youre attempting to make it look like hes leaping from one roof top to another. I suggest trying to exagerate his pose and form slightly more to give it more... energy, more movement and dynamics. Hopefully someone else can explain it better.
thanks for reply, i understood very well what you mean, will try to do what you say in fact it is a cute idea, hoping not to create strong problems in the anatomy :)
1) Lighting: Where is your lightsource? The warm light in the BG seems to have no effect whatsoever on the figure and the figure itself is lit from everywhere and nowhere, which makes it look "pasted on".
2) Perspective/scale: Perspective overall looks wonky to me. Did you plot the perspevtice or just guess at it? WHen it comes to scale, the tower(?) on the left looks like a miniature and doesn't really sit weel in perspective either.
3) Composition: You've got a few minor tangents like the figure's finger and the tower & the edge of his cape and the rooftop.
Overall the most pressing problems are with fundamentals. I recommend a lot of painting from life to understand colour and light. Brushing up yourt perspective won't hurt either. These books are great resources for those topics: Gurney: Color and Light / Norling: Perspective made easy