Firstly, I would recommend tossing the hype intro. It's been done to death, and makes you look unoriginal. It also sets up your video to be SUPER AMAZING, but then when the gameplay starts it's very...bleh in comparison.
I do like the length, shorter is better when starting out, then people don't feel like they have much to risk by watching someone new. That being said, at a shorter length, and with no commentary, you need to step your editing WAAAAY UP. It loses my interest in the first 10 seconds. The ending is a bit abrupt as well, there needs to be some kind of sensible transition or feeling of conclusion.