There is a wonderful, and possibly intimidating, amount of detail here and it's awesome! I can only imagine how long this must have taken, and the work really shows. I would edit the tones in the characters, because they're too close to the background color, and it sort of muddies together. I think it would take this piece to a new level if you brought out some of the blue in cat-noir's costume, killing some of the red and separating it in temperature from the background. The details are super wonderful here, and I think it would benefit the piece greatly to add that little bit of extra contrast.