Hands is way 2 detailed, if you're gonna mass these, then you better reduce the polies there, and let the skin do its job.
If it's a hood, then it's ok, but if not you might consider making a neck.
The oxygen tanks are good.
mask could be a little smaller, not so wide.
And the spikes on the gun seem uneccersary since it wont be noticed in-game.
This is really good, but rely on the skin more.