Do you accept constructive criticism?

Yes, I do.

Well for starters: Your work clearly shows a comprehensive study of anatomy and musculature, lovely work all in all, 7.5, 8/10 minimum.

That being said, there are some things to nitpick on:
1. one of his legs and knees is clearly larger than the other, even adjusting for perspective
2. his torso seems a hair top-heavy for the legs he's got- not overly muscled, just slightly oversized in general
3. I am begging you, if you have to do a macro scene then don't have it be with either A) little red dots on the ground indicating crush victims, or B) faceless, windowless block "buildings" the giant is posing near for the sake of height comparison. I know they're both plenty common, but that doesn't make them any less lazy or disappointing. I also know asking for details on miniature figures is a tall order, but even stick figures would be a step in the right direction.

I really do like this piece, God's honesty, I just feel compelled to toss in my two cents because I know it can be even better and you have the talent for it.

Thank you for your feedback. I will make sure to take that into consideration on my next piece.