Without mercy? Ok. The gamma looks messed up, the video is letterboxed, not a whole lot of shadows or lighting going on, no ambient occlusion? And work on your animation and camera work.

Thanks a lot for your advices!

Good start! You have some storytelling going on, but it is a little unclear in some spots as to what exactly is happening. I would take a look at this tutorial that Zachariah put up in regards to the line of action: https://www.youtube.com/watch?v=j-Uf-lsH_AQ
That should help you get clearer storytelling with your shots.
As for animation, the more you practice the better you get. One thing I think you should work on in particular is speeding everything up. I know you were trying to sync your animation to the music, but the slow motion is just not working well and honestly makes things a little boring. A lot of beginner 3D animators (including myself) tend to create animations that are too slow. Timing is half the battle with animation. So if something is too slow or too fast, you're either going to bore people to tears or confuse the hell out of them. So just keep yourself in-check when animating a long video like this.
Hope this helps and keep it up! :D

Ok thanks a lot for the link and advices!