Shooting something/someone at point blank range no longer damages you.
Regulators (the things you have to destroy to blow up the power station) have been added.
Probably rewrote lots of code.
Made people wander around aimlessly.
Made guards semi-intelligent (if they see you with a gun, they keep shooting after you put it away; if you go around a corner, they follow you).
Made mechanics go to fix any nearby regulators that are damaged.
Made explosions more painful.
Made the machine gun less painful.
If a dead regulator is fixed, it becomes unkillable (technically, it hasn’t been fixed, it just looks like it has).
Scientists and mechanics seem totally unfazed by a terrorist running around killing people.
Guards don’t seem to notice large explosions or bullets flying past them.
Guards can easily get trapped on a corner/behind some furniture.
Not enough explosions.
Not enough levels.
Still no way to win.