Avoiding Turrets
Roll all the way and, don't run, when the turrets are shooting at you. Stay on the right side by the door and wait for the target closest to you to come up. Roll behind it and wait until the gun has shot all of the target away; it only shoots enough bullets to do that. Then, the target in the middle will come up. Quickly roll again behind that one, and wait. Next, run and roll between the guns. If you get hurt, there is a medpack on the wall. Run and do a jump kick to the scientist. The guns will have destroyed themselves and you will be fine.
Defeating Algo
On the last mission, when you have to fight Algo, to kill him quicker aim for the muzzle when he fires then move up slightly and fire. This will kill him faster.
Defeating Jong Ho
Equip the .45, then hide behind the crates to the right of the full ammo supply. Place your center bead on him and fire. He will eventually die. Do not worry about getting a clear shot, as you will see with incoming enemies they will die easily.
Avoiding Turrets...