Really nice composition! Everything's in good proportion and the colors are good. The background's also pretty decent as well. Something that I usually struggle with. The arms are a bit too buff for me, though. It seems like it was intentional. Given though that she is supposed to be a ninja, it's not that far off, but I would still slim down the arms a bit. Just makes her look less masculine. That's my only gripe.
The effect that you did on the flooring to make it look reflective is really cool. That's something I need to learn how to do. Also, even with tickle pics, most of the time I don't even take notice of the feet, but you're one of very few people I've seen here that has drawing feet down to a science.
So, all in all great job. Hope to see more.