0:00-0:16: The intro sounds rather MIDI-ish, has too much reverb and sounds too wet, and doesn't give the sense of urgency that you had when you listened to the original battle. This is a *battle theme* for crying out loud! Give it justice by starting it with a sense of urgency!
0:17-0:23: Those synths sound nice, but the melody which is meant to play in this section is blending too much in the background. Again, too much reverberation from that melody line.
0:24-0:44: The bass and kick drums sound rather too soft; the snare drum is audible over those two, so it really doesn't give that much punch. Without the headset it is audible, but you might want to try turning those up. The plus side here is that the melody is audible, which is great.
0:44-1:04: Another melodic synth comes in, which is a nice change in instrumentation, but you may want to consider *layering* two melodic synths instead. Have one play the main melody just like the previous one, and then have one play the broken chords in the background, so you can hear some sustain. That'd be a nice effect, if you can pull it off. Treat the broken chords like a counter-melody, one that will bring the piece out.
1:04-1:24: There's only the melody and the bass and the drums? This makes the piece anticlimactic, if anything else. A battle theme is supposed to have rising tension, and then when the loop ends, falling tension. Instrument layering and dynamics would've been very much welcome here. There's the occasional synth, but.... it doesn't do much to build up to the climax.
1:25-1:34: HEAVENS NO. The melody is not even audible here! The strings are too blended with the background! The synth is beautiful, with all its echoes, but note: THIS IS THE CLIMAX OF THE PIECE!! Why, why, WHYYYYY is the melody almost inaudible? Why is there not an increase in layering?
1:35: Standard falling tension, which would've worked effectively had you actually taken care to build up the tension throughout the piece.
3:19: Why did the drums not fade? O_O
Some rules of thumb:
1) MELODIES STAND OUT. Countermelodies, while they are slightly in the background, can help flesh your piece out a whole lot more. That's why THEY'RE LOUDER than everything else!
2) Dynamics and instrument layering. Essentially your loud and soft, and also how many instruments play in a piece at once. This can help with rising and falling tension. Without these, the piece would (and does) soudn bland and tasteless.
3) As I mentioned in a previous review of one of your pieces: with video game music, the pieces that stand out have originality to them to varying degrees. A lot of them have the composer's personal touch, and wouldn't be note-for-note replicas of the video game themes. This one, however, is a note-for-note replica, I can pick out every note as the exact same as the original. With these video game themes we want to hear *you* -- we want to hear how you can TRANSFORM this theme into something that only you can create. Think about the good video game remixes on the interwebs: they go by that same principle.