nice variations and well done counterpoint. Besides of that a clear structure ... which maybe would be needed to be broken up a little more? Perhaps add some more surprises in the middle voices?
It is remarkable how consequently you stay away from polishing the sound or even introducing dynamics or expressions. Maybe focussing to the musical ideas themselves is the key for such a vivid output.
Nevertheless I ask myself what such a piece would sound like if polished a little bit. But I think the association I have of ... if I may dare to say ... a playmobile orchestra (and I am still not sure whether you intend this or not) comes from more than that.
One principle for understanding classical music that helped me was: Never do the same thing thrice. Twice is OK, but then change. Not even play the same note three times equally. Do a crescendo, a rhythmic variation, a harmonic tilt, whatever. If the composer did not do the variation it is meant that the musician should change the sound at least. But it helps if the composer does not repeat anything exactly too often. And be it the accompaning voices.
While I absolutely agree with Hannes' general comment about "polish" -- I think practically every piece posted here, very certainly including my own, could benefit from more of it -- I cannot say that I look for a great deal of elaborate development in such a short piece.
To me, clarity and simplicity in form and development of many of these small pieces you do is both the point of the exercise and what lends them their charm.