Since the below reviewer hasn't replied, I'll do the leg work for them. :)
Compositionally it's definitely metal. There's the staccated rhythm guitar, "heavy" sound, fast playing in the lead and heavy sounding (although more electronic) drums.
What makes it sound more video-game-y is that sound. The instruments are all virtual, none are recorded. It's so difficult to make virtual guitar sound realistic, even more so without the best tools.
For a start, the tone of the instruments you're using don't sound realistic and secondly the way they are played sounds fake. For example, in the lead, several notes in a row are the same and sound exactly the same. In a real recording, no 2 notes sound the same. The beauty is in the imperfection.
Having said that, Its a good song and I enjoyed listening. Where are you planning on going from here?