Sooo-wheeeT!
Damn you kick asses!, i should practice more on superheroes.....
great angle,and poses
just two things... superman...look cramped... ( probably due to the blurr effect, its like his head was pushed inside his body a little too much)
i would added few sharp linear highlights on the edge of the legs, and under the arm, just to show the back flames lights, the current lightning is more as if he was lightnend from above...
just a pick of mine, cuz i color using the same shade/highlight technique as you