The instruments sound pretty fake, to me. I don't have enough experience with FL Studio to help, but hopefully you know that they need to be improved.
The piano chords that are panned right are pretty loud. I'd turn them down and make them more centered. The chord clusters at 1:36 sound a bit off. You have to be really careful when you write thick source that low. I won't go into a detailed explanation, but chords in the bass are much more likely to be dissonant (even compared to the same chord a few octaves up), so yeah, watch out. In all honesty, I'd cut down the part a lot. For instance, 0:45-1:00 is just too much. Have the piano's bass voice provide a subtle accompaniment rather than playing the rhythm of the lead(sax).
What sabrigami was talking about: I'd definitely add in some variation to the tempo. However, I would not permanently change the tempo, only add retardando (temporary slowdown) at key moments. This will accentuate the more dramatic parts of the piece and add tension, making the resolution of the phrase much more satisfying.
I'd be happy to play the sax part on trumpet if you give me the sheets, or the time to transcribe the part (PM me).
Anyway, I hope this helps some. Best of luck!
Swann