Add more polys to the silhouette and take them from areas like the blue strip, lose the polys on cylinders. Are you allowed normal maps as you could transfer all that detail? Keep it up :)
The top of the head still doesn't have enough geo. You should be focusing as much of your polycount as you can on getting a smooth silhouette. Those modeled in details on the mouth are almost never at an angle where you need to care about silhouette. Personally, I would have modeled them in highpoly and baked them down to…
I think the model is pretty good in terms of shape and form. Did you use references? I think the texture doesn't work, looks kinda like a concrete wall and the dirt and wear especially around the ear is just a bit over the top. Don't mean to sound too negative, but keep up the work! Also what software did you use?
Thanks for the feedback everyone. I hopefully fixed all the mistakes you guys mentioned. I still managed to keep the poly count below 3200 tris (3192 tris to be precise) and fixed up the textures a little bit. I want to get some more feedback before I make a cleaner more professional presentation.