In this case i see just a blackground with three images you put in it. For me the idea is just equaly important as the quality of the work if not more. Sorry but doesn't make sense for me, no shadow or light work and like the other one too many thinks.
Try to give time to think on a good idea and take the time to make it the most simple and well blended possible, but of course this is only my opinion.
I think you can tone down the exposure a bit, and the purple is too much.I think i would either change the color or desaturate it a little.And most of what Argos said. Overall i think you are doing great!