That cowboy-hat dude's coat looks... kinda unfortunate. It looks like the guy is doing a jumping gym split with his legs so I would either make the coat flaps less straight or make his legs much more visible.
Also the standing girl looks off perspective wise, especially compared with the one in the car.
Overall I prefer the second, non-painted version, and depending on the quality of the shirt-print, you might want to stray away from the most thinnest lines (or at least make sure the printer can do them.)
The ground colours look muddy and pixelated probably due to using overblown textures or brushes and personally I'd probably go for less smushy colouring style and keep it clearer and cleaner.
Also make sure that the car colour doesn't overpower the girl's colours, right now she's sporting pretty pale colours.
And then God said, "Let us make man in our likeness and our image. Let us make him ridiculously hard to draw so that poor artists everywhere will have to spend 10,000+ hours failing repeatedly before they can begin to capture the form and likeness onto a two-dimensional surface." And there was man. And it was good. And artists everywhere lost their minds.
Drawing faces definitely isn't your strength... You totally need to improve in that area a lot if you wish to draw humans well. The man, for example, should have an "I'm cool and badass" face, nothing fancy but damn expressive. We have some mess there instead, if It wouldn't be surrounded with a hat and a torso, I wouldn't know it's a face.
I think you should rething the lower half of the girl... It's kinda stiff, strange, her left shin is two times thicker than the right and I can't decide if she's intended to lean into the car or not (it doesn't quite seem so but this pose without any support is unbalanced)...
Of course, the picture has good points as well, the direction seems to be pretty good just the rendering comes into the way of creating something cool that makes impact, just what suits a good comic cover (Not like I saw many comic covers in my life and many of them wasn't so wonderful either. And I'm just a beginner who never draws a real pic, with too strong critic skills and urges.)
i agree that the ape creature looks like hes holding up they guys feet- whilst hes doing the splits. I also feel that the faces of both human characters is letting the image down (more so with the woman than the bloke.) i also believe that the car and the woman need revision. Like the rest of the image however.