Jesus christ, opening sounds like something out of a video game or movie. Grasped me immediately.
Now a problem i usually face, is making an opening such as that mix with what i want to put later such as drums and a bassline. You've done it perfectly here. Despite it being short, the drums don't sound out of place, even with the orchestral feel of the song and there is plenty variation where you take out the clap, or hihat or both.
I really like the sound of this piece, it definitely belongs in a flash or movie submission here on NewGrounds, you should approach some flash producers and tell them about it! :D