really quick edit, minor for all but the hulk.

right now hulk looks like he's really apprehensive and has no neck. perhaps this is not as hunched as you were going for but maybe you see which features i changed. dropped the shoulders, elongated the legs quite a bit, brought the head up and out a little, it should now be more evident where his neck region is and how his head relates to his spine. widened the feet to give him a broader base. tried to push back the far arm as it feels like we're seeing way too much of it for this angle.
for the first dude i just dropped the shoulders to give him a more chillaxed vibe and tried to scruff him up a bit. the character still seems an anomaly to me, since beards usually signify "i don't give a fuck" and a more natural, honest vibe whereas the character looks like a hipster (are those shudda shades?) who really cares about how he comes off. but maybe this is intentional, and maybe i'm just misinterpreting the character.
also i dunno if that second guy's holding a remote or a sideways gun but i can't tell what that hand is up to.