They should have had live dismembering, where cutting off someone's limbs doesn't necessarily kill them.
Each limb you are missing, reduces your max HP by 20.
If you have...
one arm: The larger guns are unusable
no arms: No weapons
one leg: You get off your back at half speed, maximum speed is walking speed, jump height and kick damage are halved.
no legs: The most movement you can do is roll at .75 x walking speed.
Accompanying this would be a regeneration item that gave you all your limbs back, but doesn't recover health.
"I shall do as you say. I shall protect the village. I shall guard the dojo, and I shall... water... the plants."
-Beverly Hills Ninja
3 Exploding Heads