The color, lighting, and texture are what stick out to me the most. Also the characters do stay pretty true to the originals (except the moon, but I like what you did with him anyway. haha) The colors, gradient, movement, and texture in the sky is fucking fantastic. So is the subtle stone tower silhouette in the background; it's not too hard or sharp, nor distracting. I didn't even notice it at first, but when I did I was impressed. Also, the lighting on the roof of the music house came out well. And again, the complex reflections of light coming from the Blue Bubble, the poes' lanterns, and the festive lights are also what attract me most to this.
But I need to add that the composition is done very well, too, with the variety and placement of characters, making it pretty balanced (though the Gibdo on the very lefthand side is a little subtle. You managed to redeem it by adding the blue light from the Bubble's reflection on him). There are all sorts of details and several focal points which make this such a interesting painting to look at, along with a smooth, circular flow for the eye to trace.
Last note: The arm of Sharp holding up his baton is hardly noticeable. You could make it stick out more if you added more reflective light from his lantern and festive lights from above (which, logically it should be there, anyway, assuming he's not completely transparent
Hope that's the feedback you were looking for.