What makes this system so brilliant is the way that different skills and items can achieve the same results, but in different ways. There is a nanite program that converts energy into health, but if you require the same function and already have an important upgrade in that slot, use the black market version on a different upgrade slot – one that breaks down fallen enemies’ bodies and converts them to health. The hacking upgrade will allow you disable entire security systems, once you find a wall panel – but the ‘bot domination’ upgrade will allow you to take control and disable cameras, gun turrets and security robots on the fly (assuming you’re slick enough to sneak up on them).