Yeah , but everyone makes half a model and then mirrors it , its stupid to make the whole thing if u can just make half , specially for games , no one gives a crap for those tiny details in game. And even if you did , u can tweak the mirrored half if needed so it wont look 100% the same , but it's a waste of time for games.

its not a good idea to start with the entire body. focus on single parts first. create them, redo them and recreate them. Later on you can bring everything together to form a human...this itself is a hard task itself.

your biggest problem right now are (beside the anatomy) the missing edge loops (polygon flow in your mesh).
create one ear and reacreate it another way and look what method brings you the best results and why.

step by step

cheers

But it was my suggestion (good one) to make only one size of the body and then mirror it
Creating only half a body it's of'course best way and I think so too.
Maybe it's my poor English
And I've added that AFTER MIRROR! he can (but not have to) make a little diffrences on one side (just move couple of vertex) to get more realistic result.