There's not much really to say, there are only 3 major places where there was anything that could really go wrong... and you nailed them, but the piece as a whole is still rather "generic" in how it sounds. Which is still a 3 tone body with little movement.
The intro was perfect and seemed to lead into a strong piece, and the ending complimented that perfectly. But the body of the piece is bland in comparison and on small pieces you need that to carry the track and really get a good review.
This sounds more like the base of a greater piece of work, not a completed piece. With some small well calculated melody or beat alteration it could be alot greater than what it is currently.