First of all i love the collision system of the game and the dismembert issues.
Said that i would like to take it further. My idea is that some upgrades (like jetpack) adds new visible parts to the robot (like armor or clothing) and if it gets core damaged then stop working. Is continue the idea of when you have a leg chopped you move jumping or that you need the 2 arms to use the bow. Here are some of my suggestions:
-Jetpack: a thruster in the back: cutting the sides of the thruster don't makes anithing if the core gets cut it stops working. Getting the upgrade makes the thruster bigger or adds side thrusters.
-Aim time: something like earplugs that can stop a sword to the head althougth you will lose the ability to be in slow motion while aim.
-Energy capacity: every energy update adds a little battery at some place of the robot. If you get cut there the robot lose one energy bar until you get a fresh new clone (or dies).
-Kick: to kick you need to have the two legs.
If your legs are cutted but you still have arms you still could crawl to move (very slow and without jumping), but you could not use any weapon while moving you must stand still to do so.
Also this is applied to the enemies.
And one little more thing: if the barrel (the tube where explosives come up) of the spidertron gets cutted from the body the explosives will fall from spidertron instead of being magically launched at you apearing from nowhere.
What do you think of my ideas?