GRACE | Work in Progress #2

Hard for me to judge this, because, what kind of criticism are you after? Normally I look at how realistic things look, but 3d characters, especially those for games, are always a trade-off between computational effort and realism, so it's hard to judge what was a conscious decision and what you actually missed/could've done better. I guess, with rigging and animating, you can ask yourself, how many polygons/vertices you can have at most before it kills your PC and then look at where you need them the most.  I'm not sure if you know but most applications (like Blender, Unity, Daz, etc.) also use so called maps, for example normal maps, where you can add additional detail that is not actually sculpted, but just painted on top. If done well, you can cut the amount of vertices by 75%...
Onto the model, then: There's nothing wrong with the anatomy, however it's more of a stylized/comic look rather than a realistic one. If that's what you wanted to achieve, then gratz, you did it well. Not sure how hair works in c4d, but in some programs like 3ds max you don't actually need hair geometry. Instead you use splines to simulate hair/fur, etc. If such a thing is possible, you can "spend" all these vertices on sth else.

All in all, I like this piece and I find it great that you share your work process with us!

How do you rig your character? FK, IK? Also, is this going to be a character used in a game engine?