This is a pretty good idea, except for the aforementioned critiques. It shouldn't be hard to mute clips if you're going to add music to them.
Try to keep the clips short, cropping in on the best part of what you want to show. I could have sent you high-quality clips you could have dropped in if you wanted. I certainly have more footage that I have time to make videos. It certainly beats year-old footage. V_V
Also, I'm pretty sure your editing software has transitions. Try adding some fade ins/outs between clips.
I liked seeing the KK90 clips again.
Not that bad for a first video.
Edit:
Check out OCremix if you want to find some good game-themed music.
http://www.ocremix.org