Predator: Concrete Jungle

There is a weapons scientist in a depressed area of the lab. Killing him will fulfill this objective. You may want to do that after using him to unlock the retinal scanner door.

Stay cloaked and head through the first gate to kill the corrupt police chief.

Stealth kill the black ops in the recreation without causing them alarm. Use the Voice-lure to draw them out and get behind them (or snipe them).

Disable the cooling fans in order (from one to four).

At the 1-2-3-4 junction where the power core is, the weapon upgrade is on the lower level, where the mines are.

Destroy the computer in the upper levels. It may be a good idea to do this bonus mission during the boss' first phase.

The upgrade is at the end of one of the very narrow bridges at the edge of the arena.

On top of the mansion. Atttempt it after disabling all the guns and using the greenhouse on the left side of the mansion as a step-up.

Kill the Irish gang's boss. He is on the first street and easy to locate.

On the west side of the map, there was one of the lift power boxes inside a small tunnel (on the ground) in the previous stage. The weapon upgrade is in the fire.