I've seen you hanging around my Sonic compo thread, so I figured I'd comment on your track
I haven't heard any of the previous versions, but I saw you got a lot of mod feedback already, so I'm not sure what else I can add. I'd take what they say and run with it.
Overall I'd have to say the biggest thing holding this song back is the overall quality of the samples and the very mechanical feeling to the notes themselves. What software/VSTs do you use for your instruments? Sound quality isn't everything, but it's a major factory in enjoyability (for me at least). They're not terrible, but I guess they just kind of sound generic too me. Like stock instrument samples. I'd recommend playing around with the presets, adding your own effects to them, filters, modulation, maybe some vibrato here, tremolo there, stuff like that. You don't necessarily have to scrap everything you have, just try making it more your own. With that said, the piano and pads in the intro sound especially hollow though.
That ties into my second criticism, which is the mechanical feeling to the track. Every note sounds completely quantized. Like it's hitting on every beat like it's supposed to. There seems to be little movement. Like with the melody at 0:41 for example, sounds really abrupt and choppy. Try overlapping some of the notes to make it flow better (unless you're going for that sound on purpose). Adding some instrument effects like I mentioned above will also help with that "mechanical" MIDI sound. Having some of the notes slide into each other, so each one isn't hitting with it's full velocity. Just adjusting some note velocities in general should help too.
The drums also sound pretty weak to me. I'd beef them up, get a snappier snare sample, a more menacing bass drum, etc. I also have to echo what Arceace said about EQing. There seems to be a lot going on in the mid-range. The bass range sounds particularly lacking. In that mid-range, there also seems to be little variability in the instrument selection. That same synth carries the melody almost the entire song. I'd introduce a different lead or two to pass the melody between. It will help keep things interesting and not sounding the same throughout.
With all that, I'm not trying to sound negative. I really like the arrangement and think you did a great job blending the two themes (I can see where that might come in handy soon). So kudos there! I think the song just needs some work in terms of instrument selection, sample quality, and a bit filtering/EQing to bring out the best in what you do have.
Keep it at, cause I really do like what I'm hearing despite my negative sounding crits!