Wow dude I really did not expect you to do this so well!
I was going to criticize the use of Half-life 2 sounds since its not the most original idea, but once the chorus came in it hit me that this song would work perfectly in Half-Life 2. It has just the right amount of build, chorus, and falling to work perfectly in an action sequence in Half Life 2.
I will say the sounds a re used a little much, the beginning is great but the the song really needed a bit of a break at some point.
Besides that I really like your finished song.