Looks nice Coldwave.

Are these all maincharacters by the way because your fishman has about 3000 tris and if i remember correctly that's a bit high for a generic character for a gamemodel that is.

What i tend to do with Lowpoly models is start with half a model and do a mirrored smooth proxy so i will have good guidance when modeling.
Another thing is i would delete some edge loops in the fishman's tail and a cross his chest aswell only add extra geometry where there are rotating elements(shoulder/elbow etc) and if possible end all your triangles in a place where they can't see it (arm pit behind the ear under the rug you name it )

Nice models though.