Perfect Dark Zero

Will do. Thanks for the information kiomx

Here is an easy to follow guide I wrote for another potentially easy level completion.
It's for Level 12, hope it helps!
v(Stragedy)v
Swap the plamsa rifle in turret and kill both jetpack enemies.

Once dead, SWAP BACK THE PLAMSA RIFLE, then exit the turret.

Now press Y to switch yor primary weapon to plasma rifle.

Press up to "run" and move head forward (If your running towards the cliff your going the wrong way.)

Now stick to the right side, and ignore the snipers.

Run to the second temple on the right hand side, and active your invisibilty once you reach a stone laying next to the ramp leading into the door.

stay invisible and head up the ramp and when your close to the entrance shoot the two guys in front and kill the third guy standing on the right.

Now move through the door on the left and conitue forward.

After the hallway turns left and your heading outside, wait till you reach the end and turn your invisibilty back on, and walk past the two enemies standing there, and into the next doorway.

Once in shoot the guy standing in here and continue forward up ramp that leads up.

Keep following it until you reach another opening.

Here you want to engage invisibilty again and look right, shoot about 3 shots at the guy holding rockets then come back inside.

Now cover up against the edge and shoot the other guy standing up on the ledge.

After you kill him "run" to the left and head for the destroyed cars.

On the way, you'll see a room with two guys on the left, shoot them, and start shooting the stairs, until you see another eney come up and get hit by your shots.

Now go towrds the cars again to the door that you need the guy to open.

go through and continue to another door he must open.

Now you are at the part where you must run like hell and hopefully you didnt take a bunch of damage (ideally none) up to this point.

Once the door opens on the left "run" through and go until you have to drop down and turn left through a door, into a hallway that leads to the bridge.

Once on the bridge, hug the left side and allows move forward.

Once you reach the third block on the wall, activate your invisibility and run forward than left towards the stairs.

As you near the stairs "run" once you feel its safe.

Now head down the stairs and continue to the second door, enter it and shoot the three spider mines on the pipe.

Now "run" forward onto the pipe and avoid the holes in it, then go right around the piece of metal and land on the platform, where the ladder is located.

Climb up, turn right, and run as fast you can, hugging the right side of the open space.

Hopefully here you dont get damaged to much, but keep going then turn right and head up the stairs.

From here, use your invisibilty THE SECOND YOU SEE A GUARD.

Head towards the stairs on the opposite side of where you come out, and hope that you make it. If your invisibilty runs out and you start taking damage, press up to "run" and press Lb to "roll" around and avoid some bullets.

Run up the ramp and from here you must navagate through the maze of offices.

I cant remeber the exact route (im writing this all from memory) But your looking for a room that has a wall you can run behind, that leads to a big open hole that you run through to end the mission.

Hope this helps you beat mission 12 on Dark Agent.

Mission 4... The boss battle is such a pain in the ass. Most of the rest of the game you can just memorize the level, crawl through slowly, and abuse AI behavior but the Mai-Hem battle sucks. I was able to beat mission 9 (the so-called hardest mission) my second time on Dark Agent, because I ran through it so many times on Perfect Agent, but I've played mission 4 around 20 times now with no success. That doesn't even count the 5 or so times the game has frozen.

The game basically punishes you for trying to be "skilled" and fight fair, and will reward you if you meta-game and abuse the AI scripting. The Mai-Hem battle just happens to be the one part of the game that you can't do this on, and you need to just get lucky and hope another frigging ghost doesn't spawn literally inside of you and instantly kill you.