Wonderful parodious parody!
I only really played source a couple times around three months ago. Helluva good game. I recognized the map, which you expertly transposed into Flash with a consistent style and flawless perspective.
While some characters were flat and simply "placeholders," if you will, for the action to remain at the optimum level, the more unique characters, such as Dumbass really came to life for comic relief. I especially loved him and Lagger due to their completely original styles and tendencies (I loved Lagger's flicker effect, BTW). The music choice was a pretty epic combo. The Zepp Overture is a bit overused, but I still liked that it was kept constant with the whole "plot twist" atmosphere.
Overall, this was a thoroughly enjoyable flash - completely well-rounded. I must have watched it about a dozen times before reviewing.