I composed up this piece of music with no real ideas in mind. I really liked the playful motif I started with and kind of ran with that idea. As I don’t like basic and straight forward I combined secondary dominants, counterpoint and modulations. In the end, I came up with this.
Any feedback for mixing, arrangement, structure, etc is appreciated!
That’s a lot of modulations in there. 
Now onto the technical aspects, I have a feeling the sub frequencies on the piano can cause a bit rumble if not cut sometimes. You can always cut the frequencies below to remove the rumble. Other frequencies happen to be clean and nice, but it is more warmly balanced, which is not necessarily bad.
It is indeed a playful motif throughout the entire piece. I have no complaints about the arrangement and structure. You should extend it…