Good melody
You have a good ear for melody. I do agree with skyood, however, that the left hand isn't as good as it could be. However, I don't think you need to get rid of the standard 'oom-pah-pah' figure in the bass that is so common to waltzes. You simply need to re-harmonize the piece so that in the left hand, the first note of every measure forms a clear melody. Use inverted chords and change the harmony where you have to in order to make a memorable *and singable* bass line. Try to make this melody go in the opposite direction of your right hand as often as possible.
If you do this your music will sound very interesting and 'full' (not to mention impressive). You will have a good melody in your right hand, a countermelody in the bassline (beat 1 of every measure) and a chordal accompaniment (beats two and three of every measure).
Good luck.