I liked it actually, it has a very nice rhythm and the synchs are well emphasized. I agree with Bloodtimo on the problems of quality of some clips but ALSO some older gintama scenes are deformed, be careful when using 4:3 episodes you must crop the up and bottom parts before converting to 16:9.
There aren't many but your cam moves are a bit random and rough. Also, it's a pity that you had to use so many gintama footages at 1:48, I guess you ran out of other scenes but it's still breaking the homogeneity.
The fonts in the outro are really bad. Keep them simple. And the audio cuts very abruptly you should have make it fade out.
But overall it's pretty cool, good job, keep it up!
PS: Go introduce yourself http://sora-to-kasai.forums-actifs.com/f1-presentation
and next time write the name of the video in "Titre du message" and give a small description at least