For a start, we are only allowed to do a certain amount of cards as a puzzle set, so I am already working in a more cramped space. I am also adding a few more Avengers in for good measure - including Wasp and Scarlet Witch. Also they are comic book style, as opposed to movie - and no guns (SO many rules Disney! Haha). May even re-hash Wolvie while I'm at it considering the new movie is coming out soon and who doesn't love drawing that yellow spandex.
I have already taken Shon's suggestion and drawn a Mysterio (circa crazy fishbowl head). So if you have any more Spider-Man favourites I will let you know if I can add them to the pile. (Quite a few are off the list for Copyright reasons - Fantastic Four and Gambit for example).