I can suggest a few things...
Alright so there's a few things that could be used for improvement upon first listen.
The big thing is that it sounds like there needs to be more added to it besides a bass, piano and drums. I don't know what I would recommend, maybe acoustic guitar to go along with the bass rythm or a lead guitar to go along with the piano melody.
The snare drum seems a little too quiet, if you can turn that up that would make a better impact upon the song.
The ending seemed like it came from out of nowhere, the rest of the song seemed to have a quiet and calm feeling, then at the end just a bang. I would say to have a better buildup towards the end and then go from there. I would personally say to have a small dying effect after, such as adding a bit of delay after each note on each instrument. Or you could have an abrupt ending, and have alarger impact on the ending by doing that.
Other than that, the song was really catchy, the way you used accidentals had a neat feeling towards the song. Also the song had a generally happy feeling towards that.
Hope this helps.