Amateur Failure

Last week I was working on the cover for an amateur attempt of a one-shot manga. C:

I've been developing the story and characters for some time, with the supervision of a japanese friend whose mates are willing to lauch the first rookie and national manga magazine on the city I'm currently living. It was rejected, so I was wondering if I should keep with this since I don't know if it has any real potential. Any critic will be well recieved.

 Spoiler

it looks amazing if you ask me.

It's only an amateur fail because it looks professional.
Very well done.

I don't know what the person in the back is doing. The neck/shouder area is very muddy to me, like the right shoulder looks dislocated. You should try taking their pose/the pose you wanted to do because I think it's also a perspective issue.

The guy in the front has really poofy clothing. Not sure if it was your intention or not with the top, but the shorts look weird. I feel like you could pull his upper body more because it looks like it's all on the same plane. It's like he has a really short torso and is leaning forward slightly.

Nice job on the foreshortening overall. Very clean. I like your style, but a lot of parts just feel flat to me.