You wake up after a half-year surgical operation on the Citadel Station only to find out that you’re one of the few survivors. Other people are either killed or turned into mutants. All robots and defensive systems act against humans who were lucky enough to stay alive and sane. AI named SHODAN (Sentient Hyper-Optimized Data Access Network) plans to destroy the entire Earth population with the laser. You have no choice but to destroy the laser before anything bad happens.
Level 1: Hospital Level
Alright, time for action, and you don’t even have any weapon, so scout the room and take everything you can find. Don’t forget to search the suitcase and upload the data to learn the code (451). Destroy a few robots and security cameras with the pipe. Use the Medic Autodoc and Recharge Station.
Enter the code you’ve recently found and exit the room. The lift on the left can be opened by solving a hacking puzzle. You can go down now, but that’s not necessary. Better take a Group-1 card in the room nearby and search the warehouse #3 to find a few useful items.
Open the huge doors and get to the main hall. Don’t forget to get rid of mutants, obviously. Turn left and search the section you’re facing for some items including MED-1 access card.
Proceed forward, slaying enemies, picking up useful items and doing other stuff which is so popular in videogames. While in the wide square corridor, you will see the Recharge Station. After you make a few more steps, you will encounter a Hopper – a really annoying hopping turret (hence the name). Usually it can move and chase you, but right now it can’t due to level design. Just get rid of it with firearms hiding behind the corner.
Use the elevator to reach the office of Nathan D’Arcy. Pick up the gun, the access and the note how to destroy the laser. From this note you learn your concrete task which is not just wandering and killing bad guys.
Ride the elevator down and turn left. Proceed further to the security room destroying cyborgs. Did you notice that new enemies are tougher than mutants and can attack you before you even notice them? Anyway, proceed further until you see a cyborg production facility. You will notice the HERE graffiti or sign or something, hard to miss. Open the door by hacking the lock nearby.
As soon as you reach the cyborg conversion, pull the lever. That will deactivate the cyborg mode and activate the normal mode. That won’t decrease the number of foes or prevent them from respawning, but once you die, you will be resurrected. Sadly, each cyborg production facility works only on its level, so if you die on level 2, you can’t be brought to life with level 1 facility.
Go “north-east” (upper-right destination since there no points of the compass in space). You will see a few deactivated cyborgs. Destroy them now so they won’t bother you later.
Scout the rest of the deck – there’s not much space left to search. In the rightmost part of the upper part of the map you will see 4 security modules and a few monitors with constantly changing numbers on them. Destroy all the modules but make sure to keep your distance since they explode upon being destroyed.
As soon as you’ve got rid of all the modules, you will receive a creepy message from SHODAN, security level will drop down dramatically, but the most important thing is that the numbers on the monitor nearby will stop changing. You will see one number – write it down.
There’s not much left to see here. If you’ve dropped the security level down to 0%, go to the lower right part of the level and open the secret door for some goodies. Any way, get to the only elevator here since it’s unlocked now. Prepare your best weapon, heal your wounds and go to level 2. Don’t forget to close the door of the elevator or you won’t be able to press the level button.
Level 2: Research Level
There are no Medic Autodocs here so you’ll have to use items or visit Hospital Level for healing. More to be told, as soon as the doors to this level open, you will fight a dozen of mutants! Get rid of them, make a step to the hall and look around.
Alright, this level is much more difficult to beat than the previous one. Instead of weak mutants and cyborgs you will encounter Hoppers, Security-1-Bots, Virus Mutants and others. And they will be respawning over and over again so you will have to learn how to sneak past enemies... or just save often. But good news are that once you disable robot production, they will stop respawning. That’s the only level on which you can stop enemy production.
Scout this level, destroy some mutants and robots. Sooner or later you will find that in the center of this level is a big room (locked for now) encircled by a square corridor. There are several doors and passages leading out of the corridor to different rooms and halls. Your destination is a big double door in the “southern” part of the room, but it’s also locked for now.
Alright, back to the mission. Look for the damaged room in the “north-east” part of the level. It can be accessed via the corridor in the “northern” part of the central square corridor. You will see a Recharge Station and four levers. Pull one. There’s only one lever you can pull, other ones are jammed.
Now you need Science Access Card. That can be done either by destroying a really tough robot or by hacking through cyberspace. Both cyberspace terminals are situated in rooms which can be accessed from the very “eastern” corridor.
Now you need laser safety override code (199). Either solve a hacking puzzle or hack into cyberspace from the terminal nearby. In cyberspace you can also get you Group-4 access.
Go to the square corridor in the center of this level. In its “southern” part you will see big double doors. Open them and get ready for a fight. Destroy all the robots there and take an Isotope X-22 from the lab to the right of the double doors.
How head to the opposite part of the “southern” corridor. Read the piece of paper on the floor to get the code (623). Hack the access panel nearby. You will gain access to the key panel. Enter the newly-learned code to cancel the robot production on this level. Spawned foes won’t disappear from the map, but they will also stop reappearing. Neat!
Head to the room with security modules and destroy them. Careful! Once you do it, doors nearby will open for you to meet new portion of enemies. After securing the area write down the number which appeared on the monitor. Now proceed to the elevator to the Reactor Level. It’s not the same elevator you’ve used to get here! Go to the “southern” one nearby.
You will have to visit this level for a few more times. There are some puzzles you can’t solve right now, so don’t get upset with some areas impossible to reach. For now head to the right and go through the door. The door ahead of you contains the cyborg production facility. Activate it now. Now, facing “north”, enter the door to the right (not the one you came through, the next one).
You’re in the medical area. Solve the puzzle to gain access to the Medic Autodoc. Proceed to the end of the winding corridor and press the button. You will see a white noise for a fraction of a second, and a voice will say about successful radiation treatment. That’s not mandatory right now, just remember this place. This might save your live in the future.
Now you need the most “southern-western” room. You can reach it by going “west” from your current location either by “north” or by “south” corridor. Just place the Isotope X-22 to the Radiation Shield Generator. If you don’t know what Radiation Shield Generator is, just try to insert Isotope X-22 to every possible slot until it fits. Pull the lever nearby to see the process of power shields activation.
Now head to the “northern-western” part of this level, dealing with enemies on your way. If you did it right, you will be in the corridor, and the door to the room “south” of you will be a bit “east” of you. Save your progress!
Step inside the room and get ready for an ambush. The light will be turned off, the door will be closed behind you and enemies will emerge. If you don’t want to fight all enemies at once, run to the small room on the left and shoot foes one by one.
Now to the Safety Override Access part. Once inside, follow the blue carpet (or whatever it is), turn right and go up using the gravity lift.
Enter laser safety override code (199) and pull the lever. Laser Safety Interlock Disengaged should appear on the monitor. Your job is done here for now, head back to the elevator.
Level 2: Research Level
Go to the central part of this level. You will see a bunch of enemies there. Get rid of all the cyborgs. Beware of energy mines – they drain your energy, obviously. Once you defeat all the enemies in the hall, look for a small control room and press the big button there. You will activate the laser. The first part of SHODAN’s evil plans has failed.
You could have pressed the big laser button before even accessing the Reactor Level but if you would have done that before activating the shields, you would have achieved a non-canonical “humanity destroyed” ending.