What about bringing simulation of amputations into this game?
High calibre ammo and explosive rounds can pretty easily cut-off your limbs.
I think It won't be that hard to simulate. With PhysX It should be even easier.
VBS2 does simulate this (http://www.youtube.com/watch?feature=player_detailpage&v=Oe-JDBS4bZ8#t=19s)
SLX mode in A2 simulated this too..
BTW There are similar tickets like this, but not 100% exact.