First of all I'd like to agree with Guru and Mark, it definitely needs a voice over. Not only would it help explain what you're doing, but it will also allow the cheesy background music to actually be background music. The video will also seem to flow more quickly and hold more interest.

Secondly, That police character looked like it was computer generated, and if that's the case why not render it out with an alpha channel instead of messing around with a <b>Luma</b>Key?