Need critique on this sort of futuristic rock piece.

First things first, decide what your goal is. If you're writing a rock some with some filling out, record it, don't midi it. Other way around? Add some more instruments to make them seem like the focus.

The drums are a bit simple, you really need to do something more than just metronome it. Get some toms, some off-beat accents, something like that. You had one cool fill in there.

The bass lines are nifty, but nothing really stands out. I really don't feel the guitar lines are well thought out, just something a bit crunchy. Look for melodic hooks, little phrases that you want to bring out in the lines.

1:00 of music is very little, even for a incomplete piece... where are you planning on going with this?

It's definitely got potential. Do you play any "rock" instruments?

Gherkinbonbon is right, and... It all seems a bit inconsistant. There's no theme or gripping motive, and it comes across as inconsistent; you need some kind of plan as was mentioned or it will just sound like a series of riffs stuck together like a medley.

I think, although rhythmically and decoratively it's quite boring, and needs some more work, you have a pretty sick (as in awesome) moment around 25-35 seconds, with the synth voices. There is a harmonic change that really works, and you could think about using that kind of thing more.