I took a look at it and the first thing that comes to my attention is that you need to properly outline each character so that the viewer can identify them easily. I see you like to use open lines and thats ok as a style but in the "Super" artwork I would have tried to better mark the different foreground characters with lines going thicker to thiner.Thats just my 2 cents, for the rest its ok, I mean your 16 right? You're better than me at that age so you have a bright road so keep it up