Nice Shreddage!
Your comment on theory made me smile, so I had to write this review. Your theory is in fact rock-solid. The melody is written very well. The end chord is a little bit bizarre, and I feel like you could've added a few different things to make the song more interesting. Maybe another guitar/bass/synth, maybe a more interesting drum part. But in regards to the guitar, it's very good.
Boo to whoever gave you a 0, it doesn't deserve it, so I"ll do my best to "even it out" with a 5. For the review's sake, I'll give you a 7/10 for a good melody.
P.S. Yikes. My 5 only raised it 1.32. That suuucks.