I have thought of an idea,it's kinda like Dead Space, Fallout or Cortex Command where specific parts of yours or enemy's bodies be injured with consequences.For example,if you fell from some height,your leg would be injured and you would walk slower\not able to jump.or if you were shot in the arm,you would be less accurate etc....There should also be some sort of display showing the condition of your whole body.This can also be used against the enemy,where certain enemies have a specific weak point where you could just say, shoot a fast enemy in the leg to slow it down then kill it,or server it's hand so it can't attack.Certain enemies can be killed by hitting a specific spot.I kinda like the idea of actually aiming rather that just spamming.
It is quite cool, but there may be a problem implementing anymore than things like headshots, not because of the graphical work required but in 3D models it's much easier to designate a certain spot to take more damage or to disconnect the model there, but much more difficult in a 2D game where your character is technically just a single image. This can be worked around but it sounds more like a post-release idea for me.
I think it'd be especially difficult considering all the different forms monsters can take. Maybe unique bosses could have this function, post-release most likely.
Well each monster does technically consist of pieces, because of the generator, so they might use that if they tried doing something like this.