It looks good from front, but backside is still looking weird and unfinished.
There is not much you can do with helmet right now, but you could change torso to be a little bulky, so that there is no visible seam between helmet and breastplate on his back.
I'm also not sure with those hoses on the helmet, could've they be bigger?
Also that filter on the mouth is looking somewhat small and way too light, checkout big renders like
Absence of that nightvision also makes some difference, but I understand it's just a detail.
Lighting is a bit off, but guess it'll need some engine update to get it working as on sprites.
Also is the size of model intentional? It looks smaller than original.