I like the melodic ideas going on here, and the doowop progression is always a solid base to work from. As mentioned, some mixing would enhance the experience - the piano, especially, takes up a lot of space for such a simple line, and backing it off some would offer the lead voice(s) a little more room.
I'd also like to hear some elaboration on the drum part - nothing too busy, but some variation as the melody builds could help strengthen the overall sense of progression within the framework of the 4-chord loop.