Interesting idea for a song. I'm surprised you made that tune work. It didn't seem to be all that melodic of a tune to go off of.
-As I said - I'm surprised you managed to make the main tune work. I do have to give some credit for that.
-Mixing's fine. I can hear everything, don't hear any static or clipping or anything.
-The intro. The piano really doesn't sound too good. You may want to look up a better piano sound, for one, and for another, the way it fades out without going anywhere doesn't appeal to me at all. I'm betting quite a few other people would agree. Essentially: The piano initially doesn't sound too good, and the transition isn't that good either.
-At around 1:20-1:30, I thought I was hearing the next section coming. However, lowering the cutoff after that was fairly displeasing - even in techno, that normally doesn't happen. The subtle bringing-out of a new melody is more common - reason being it sounds a bit better.
-After the lowpass, things stay like that for far too long, only really coming out again at 2:45-2:59.
-You missed one of the most valuable and most-used tools in the EDM catagory! White noise filter sweeps! ;) They really add a lot of tension to a song, letting you release it in a much more satisfying way. It also fills out the high end of a mix more.
-No outro? Tch. Try something a bit more than a fadeout and/or flat-out stopping the song.
-There isn't really much variation at all. You brought down the cutoff and brought it back up again after the little piano section, and that was about the extent of variation. Try adding in multiple melodies/tunes and switching between them/layering them together. That adds a lot more depth to a song and helps solve variation issues. Same with the chord progression.
Overall: I'm going to have to give this a 1.5/5. You seem to have mixing down, but there's a LOT more that could be done with this song. I'd suggest checking over some of your favorite artists and not just listening to their music, but analyzing it. What kind of things do they do, and WHEN do they do them? There is a method to the madness, after all.
Thanks for the critique. This actually helps me a lot, seeing as I am still a noob at all of this and the only feedback I've gotten is the review before you and feedback from friends, which is usually biased. You brought up a lot of good points in this and I'm definitely going to try and implement the tips you gave in to making my future pieces even better.
Simply amazing! : ]