First of all... wave file? I don't have FL Studio to say it, but can't you use .ogg or .mp3?
Second: The percussion is too loud. For that theme, you shouldn't use percussion so loud. The piano too, is so loud that I can't hear the flute after it enters. If the flute is the main melody, you should keep it the loudest instrument. Also, you shouldn't enter the percussion before adding a harmony, it doesn't sound much smooth. (suggestion: maybe ensemble strings and a harp could fit, though it's up to you)
Third: The piano melody alone sounds good; the flute melody alone also sounds good, but their melodies together don't match.
Fourth: The speed of the piano is okay, it doesn't matter if it's fast, as long as you diminish the volume. The important is the speed of the main melody (in this case, the flute), which is up to you, though I would use it a little slower.
I hope that helps you improve. Anyway, good luck with trying FL Studio.