Your armor looks to me like just a bunch of random extrusions, it lacks in actual realism and just generally doesn't look good, you need to add more dimension than to just extrude faces and call it an armor. The helmet being the most major proof of this since it's basically just a bunch of extrusions in and out.
His little weapon looks pretty interesting though, if you fine tune it a little bit it'd be very cool.
Because you actually extruded the armor faces from the faces of the body instead of modeling the armor separately and saving polygons you have added a bunch of unneeded divisions which really don't give the model any upper hand design-wise at all, and are needed deletion, your base mesh could probably still maintain the same shape but with 1/3 of the polygons it's utilizing at the moment.
Human anatomy wise he seems to be lacking a shoulder, it appears as you just extruded the arm from a hole on the torso (Which is the natural thing to do, but tends to leave a bit wanted on the shoulder), and I believe your crotch is a bit flat, the hip usually tends to rotate upwards quite a bit in the X axis (Look up some anatomy shots and I believe you'll see what I mean) which probably isn't necessary to actually model in but it probably helps to keep it in. Think of the crotch (Without the legs) as a V-shape where the legs are meant to grow out of the two outer sides of the letter and you'll understand what I mean.
Looks good none the less though, as usual keep it up and such.
Alucard94, the member of the future of the past.
