Assault on the Control Room
--== Enemy Units ==--
(1) Grunts -- A mixture of both types / a lot are asleep so melee them
(2) Jackals -- A mixture of both types
(3) Elites -- All three types are present / Type-3 are mostly invisible
(4) Hunters -- Appear in pairs
Level Notes: This is probably the longest level in the game -- it sure felt like it anyway! If you have been following the guide you will be able to unlock the following Achievements on this level:
-- Skulls Taken! (25 GS) Discover half of the skulls hidden throughout the Campaign
-- Heavy Reading (25 GS) Read half of the terminals hidden throughout the Campaign
-- Wraith Hunter (10 GS) Destroy 4 wraiths on the level “Assault on the Control Room” with a scorpion tank
-- I'll Take That (25 GS) Fly a Banshee on the level Assault on the Control Room
-- Assault on the Control Room (25 GS) Complete the level Assault on the Control Room on any difficulty
The level starts with you being dropped inside the facility -- there is token resistance, some Grunts and an Elite who you can easily manage, but as you progress through the building the resistance gets a lot stiffer. In fact this is one of the levels that even on normal will be trouble for you of you try to rush through it or take a gangbusters approach -- you will need to use a mixture of stealth (where you can) and calculated shooting where you cannot.
After you work your way into the first control room you will notice a vent opening in the center of the chamber -- grenade jump up to the pillar in front of it and then jump the gap and grab the Fog Skull from inside the vent while you are here.
Now head outside -- you have a choice to make here -- if you are going for the optional Achievement for killing the four Wraith with the tank you need to head to the right and down the drop into the next area and grab the Scorpion Tank, then turn it and wait for the Wraith from the first area to follow you down into the lower area, and take it out. With the first Wraith dead, proceed ahead, using the tank's MG to take out the ground forces and then its cannon to take out the second Wraith.
The third Wraith is on the ledge above the tunnel leading down to a door you have to open with a control panel - it will move from side-to-side on that ledge to avoid your shots -- but you need to take it out -- just be sure you take out the turrets in this area first, and the Banshee that is providing air cover BEFORE you try to angle in and take out the Wraith above, as otherwise you are likely to end up dead.
With the third Wraith out of action, head down into the tunnel, open the door, make your way through the tunnel and open the door to reach the next area -- which is a bit tricky because you have to maneuver the tank around to the left and across a bridge to reach the exit from this area, clearing out the defending troops as you go. Once you have the defenders cleared out but BEFORE you exit this area go back to the other side we entered from and look down on the ledges below and you will see the second Skull for this level!
The two easy to miss Achievements
The Fog Skull
Jump down and grab the Malfunction Skull FTW, and then jump back in the tank and exit the facility to reach the next outside area and your final Wraith! Once you take out the fourth Wraith the Achievement Wraith Hunter (10 GS) unlocks. There will be some Ghosts and ground troops, including a pair of Hunters to be dealt with, but good on ya mates!
Continue along the path taking out the mixed enemy units including some Hunters, air cover, and ghosts, then move to the other side of the area and use the door to continue along the path, entering another facility. Clear out the bad guys and take the lift up at the end to the upper area and work your way around to the exit to the second skybridge, where you just do more of the same, taking out the enemy.
When you exit out the other side into a long corridor you will face a Type-3 Elite with a sword who is invisible -- take him out and then exit the facility to the outside. This is the part where you need to grab one of the two Banshees that are parked ahead -- so rush forward shooting the enemy and grab one of them to unlock the Achievement -- I'll Take That (25 GS) -- and then land the Banshee below and you will see a structure you can go under -- go to the bottom and you will find supplies, a Rocket Launcher, and a Sniper Rifle, as well as the Terminal for this level -- use the Terminal to unlock the Achievement Heavy Reading (25 GS).
Note: if you fail to grab the Banshees you can reach the bottom area by heading into the other side of the facility and taking the lift down, which puts you right next to the area you need to drop down in to get to the supplies and Terminal.
Battle your way up the ramps to the top of the area taking out the mixed units including several groups of Hunters, and then open the large door and take out the defenders there, then another pair of doors for a CS with Cortana that goes a little sideways... She integrates to the Control Center Computer and then freaks out on us, telling us we have to stop Keyes but not why...
That ends the level, unlocking the Achievement for completing it.