"it looks too 2d" isnt a crit, tell him what the actual problem is, cuz your "crit" makes no sense,
anyways, it had some potential at first as being one of the best skins shown around here in awhile, but the arms dont even come close to the quality of the face, and really ruin the rest of it
the shading and muscle placement is horrid, looks like some of ultra's style on the arms, (in other words, very very bad) and that chest isnt any better, mostly the way you shaped and colored the muscles, they look more like streaks of mud than muscles,
if it were my skin id redo the chest and arms completely, dont get me wrong you DO have potential, if you can recreate the same style on the rest of it as you did on the face then it will be great, but as is, its just...blehhhh