I am making a sci-fi game. The setting is a future society dominated by a totalitarian and technological government. Think 1984, Brave New World or even Matrix, but not THAT technological.

I am in the planning stage, so I make sketches of how the finished renders and images should be. Here is my first one, it is the guard/soldier of the government (evil guy):

http://bb.xieke.com/files/fiendekonsept1.png

He has a hood covering his entire head, and a device (the white thing) that feeds him with video, audio and smells etc. from the world around him. He also receives tactical information. What could or should be better? What do I need to keep?

This will be a 3d render

What sort of view point is this game going to have? First Person? You will want different amount of details depending on how close we are ever going to get to this guy's head.

I suspect you didn't really do much exploring with your concept, and just went with the first idea you had, so my first suggestion is simply to try playing with the shapes. Personally, I would make the camera eye much bigger so that I notice it right away, and find something more interesting to do with the straps.
I would also suggest painting the entire figure, making sure the entire costume fits together and looks cool.
You may think you have a clear idea in your mind of what this looks like, but I think you may encounter some problems once you start sculpting it, even more so if you will be handing this off to someone else.

Thanks I will look into this and post the next result.