Office Complex
Office Complex is about the size and difficulty of Unforeseen Consequences. You will start to battle one of the most common enemies, the Vortigaunt, and have to fight some Bullsquids (a long with some headcrabs and zombies of course). It takes place in several Black Mesa administration facilities, which of course, have been overrun by the aliens.
When the elevator reaches the ground floor, the doors will open. Take the battery and the medkit (if you need it) that are nearby. Do not walk up to the red double doors just yet, and do not walk past the vent shaft. Wait for the fallen light to kill the headcrabs and then walk up to the vent shaft (but don't go too far past it, or you will take some major damage from the light). The electricity from the fallen light will destroy the vent shaft, granting you a passage. Crouch down and take a right from the vent shaft entrance (we'll go back to the left passage soon). Keep going until you come to another grate, which you must destroy. Inside the room are two scientists, and one of them gets dragged up by barnacle after he gets scared. You can let him get killed by the barnacle if you want, because he serves no purpose. Barnacles will then begin to come through the ceiling, so watch your step.
Go through the doorway labeled 'DANGER: HIGH VOLTAGE' and press the switch inside. This disables power throughout the entire facility (including that dangerous light). Go through the double red doors and back into the hallway. Before we go to the next area, go back into the vent shaft and take the left passage. Keep following the path and it will lead to a fan, where a dead security guard with three clips of pistol ammo lies. Shoot the three headcrabs from behind the cage with your Glock, and then claim the ammo near the dead guard. Exit the vent shaft and go the end of the hall, where you'll have to destroy the window with your crowbar. Crouch jump through the window, and take a left. This is the main hallway. Go to the very end of hallway, past the storage closet. We won't worry about the other rooms for now.
Smash all of the wooden crates with your crowbar as you go down the hall. Be careful though, because behind the largest wooden crate is a sneaky headcrab. I suggest throwing a grenade behind the crate, because the blast will be more than enough to kill one little headcrab. If you don't have any grenades, you'll have to risk being bitten by the headcrab as soon as you go past the crate. Smash the large crate after you kill the headcrab, and then keep going down the hall, which leads to a security checkpoint. Grab the shotgun and shells off of the green box to the right and walk up to the gate, where a security guard is. I suggest saving the game before you walk up to the gate, because we'll need that security guard to unlock the gate (it leads to four boxes of shotgun shells, three pistol clips, and a medkit). As soon as you walk up to the guard, a zombie will emerge from a nearby room. Immediately kill the zombie with two double-barrel blasts to the head (secondary fire, default: Right Mouse Button). Once it's dead, the guard will gladly open the door.
Collect the shotgun shells next to the security guard and have him follow you into the next room. Grab the three boxes of shells, pistol clips, and medkit if you need it. A headcrab will jump from a vent shaft up above, but the security guard can handle it no problem, so just have him kill it. Walk back to the platform and descend the ladder. Smash the crate next to the ladder for a medkit, and the two other crates for one battery. Climb back up the ladder and make sure the security guard is following you. Retrace your steps back to the main hallway and have the security guard wait by the double red doors. Walk up to the storage closet and a zombie will burst from it. Walk back to the security guard and double team the zombie. It should be dead in no time. Grab the two clips of pistol ammo in the closet and have the security guard stand in front of the broken window. He should be able to kill the headcrab that's in the next room.
Now have the guard wait in front of the window and crouch jump through the window. This room is completely flooded with electrified water. Jump on the white table in front of you, and then do a diagonal jump to the sink on the right. It's alright if you fall into the water, because it does very little damage (just make sure you go back on a surface right away). Do a small jump to the health station and use it if you have to, and then jump to the small lightswitch that's to the right. Press the light switch and the water will no longer be filled with electricity.
Walk up to the vent shaft nearby and turn on your flashlight (default is the F key). Smash the grate with your crowbar and immediately take out your pistol. Shoot all three of the headcrabs that are up ahead and then crouch jump into the shaft. Now make sure you stay crouched, because as soon you stand up, a fan will kill you instantly. Keep following the vent shaft until you get to another grate. Destroy it, and then go through. You will fall into the hallway that was behind the locked double red doors. Open both doors and make the security guard follow you again. Go back to the double red doors and walk down the hallway. Two headcrabs will fall through the ceiling, but just have the guard kill them both. Have the security guard wait near the single red door in the corner (make sure he's not directly in front of it). Now push the large blue crate directly under the gray ladder that's up above (where the headcrabs came from). Push the smaller crate next to the big one, and then jump from the small crate to the large one. Look up at the ladder and jump, and then climb up to the top. Jump off to the left and go up to the grate. A headcrab will be nearby, so kill it immediately. Destroy the grate, but don't drop down yet.
Wait until a scientist comes and gets mowed down by a turret. After the scientist is killed, a headcrab will come. Wait for the turret to kill the headcrab, and then look at the large blue crate below. I recommend saving the game at this point. Now jump down and quickly crouch behind the blue crate. Keep pushing the crate foward until you're under a platform, where you'll see a switch. Press the switch and the turret will be disabled. Smash the wooden crate that was next to the blue one for a clip of pistol ammo, and then go through the doorway next to the dead scientist. To the very right of the room is a shotgun and box of shells, and on some shelves nearby are two pistol clips. Now open the door at the end of this room, which will lead back to the security guard you left behind. Have him follow you back to the turret room, and then have him wait in front of the large passageway on the left. Equip your grenades and walk down the hall, where you'll notice six headcrabs are waiting. Throw a grenade into the center of the group and run back to the security guard. Have him follow you through the hallway, where he'll pick off any survivors. Now go up the stairs, where another security guard is shooting some headcrabs.
Have this security guard follow you and go into the next room (so now you'll have two security guards following you). Walk into the checker tiled room, and a headcrab will immediately emerge from the ceiling. The security guards will kill it in no time. Now go through the first door you see on the left. A scientist is trying to help another escape through a vent shaft...but something bad happens. Next to the T.V. is a battery and medkit, so grab them. Walk out of the room, take a left, and stand about five feet away from the first intersection. Take out your grenades and throw one to the first passage to the very left, killing a Vortigaunt and a headcrab. Now throw another grenade to the second passage on the left, which will kill a lone Vortigaunt. Take out your shotgun and turn to the right. Immediately shoot the Vortigaunt with two single barrel shots to the head, and go towards the green tiled room (where a dead scientist is).
A headcrab will come from the ceiling, but the guards will kill it. Go down the dark hallway in this room and kill the Vortigaunt hiding in the corner. Turn around and you'll notice a Vortigaunt behind some glass. Shoot the glass and then kill the Vortigaunt (collect the pistol clip from this room too). From the second entrance to the dark hallway, go all the way down the hall into another room (an entrance to another hall is directly to the left of it). A headcrab will emerge from the ceiling, but the guards will kill this one in no time. A health station is right next to the open gray door, so use it now. Now go into the hallway that was right next to this room, and kill the Vortigaunt that's hiding in the corner. Have the guards kill the Barnacle, and then walk into the room the Barnacle was next to. Inside are two scientists and a medkit on the table. They can't do anything, so just leave them here.
Go back to the green tiled room (the one next to the first entrance to the dark hallway) and look for a sign that says 'Maintenance Access.' Shoot the gray colored tiles on the roof to reveal a secret ladder. Climb all the way to the top and press the switch you see in front of you. This will disable the turret nearby, and grant you three boxes of Shotgun shells under it. Now smash the window next to the turret and throw a grenade from the top (make sure it lands right under the window), killing three headcrabs. Climb back down the hidden ladder, and take a right from the first green tile room entrance (the one to the right). Take another right and you should see some soda machines. Make sure you have the guards following you. Take out your grenades and throw one in the corner of the orange soda machine, where a Vortigaunt is hiding. Keep your grenades out, and throw one through the next doorway, which will hopefully kill both Vortigaunts. If they're still out there, just kill them with your Shotgun. You can smash the nearby crates for a medkit, and when you're done, go into the next room. Have the guards kill the Barnacle, and then use the Health Station next to the scientist. He doesn't serve a purpose, so just have him wait there.
Now go up both flights of stairs (make sure the guards are behind you) and walk through the red doorway. If you didn't kill the headcrabs from the turret room, just have the guards do it. A Zombie will be nearby, so just have the guards double team him. Keep going down the hall and take out your grenades right before the intersection. Throw one from the intersection and run back a little. This should kill the two Vortigaunts that were next to each other. Pick them off with your Shotgun if it didn't. Go through the red door at the end of the hall, where you'll see another security guard and a health station. That's right, three security guards will be following us soon (if they didn't survive, that's ok, because we'll only need one for the next area). Use the health station if you need it, and then have the guards follow you down the ramp nearby. Take a right from the bottom of the ramp and go down another, where a bullsquid is waiting. Quadrouple team the Bullsquid, and he'll be gone in about three seconds. Collect the shotgun shells and grenades next to the dead scientist, and then walk back up the ramp. Two Vortigaunts will spawn once you do, so kill them quickly with your Shotgun. Now have the security guards wait at the bottom of the first ramp, and then go back up toward the health station. Behind the red door is a hidden vent shaft. Smash the grate and then go on through.
This vent shaft leads to a hidden room, filled with four boxes of shells, ten grenades, three pistol clips, and a health station. Getting there though, is an adventure. Keep following the vent shaft until you get to a ladder. Climb up and walk across the tiny pathways along the sides. You'll notice a fan with a broken wing that is blocking the next area. Jump over the fan right when the broken wing is in front of the entrance way. Jump over the steam pipes next, and then keep following the passage. You'll notice another grate with two headcrabs behind it. Smash the grate, switch to your grenades, throw one in there, and say bye to the headcrabs. Go through this vent shaft and you'll end up back in the hallway with the two Vortigaunts. Crouch along the tight pathways until you reach another vent grate at the end. Smash it and go on through.
Go all the way back to the security guards and have them follow you again. Retrace your steps back to the cafeteria and have the guards kill the zombie that's enjoying a meal. Before we go any further, have one security guard wait at the top of the staircase, the other in front of the railing next to the staircase, and the other a couple of feet next to the red doorway on the other side. Walk up to the wooden barricade in the cafeteria, and six headcrabs will burst from the ceiling. The guards will kill all of them in no time. Have them all follow you again, smash the barricade (make sure there's enough space for them to walk through), and go all the way down this hallway. The hallway leads to a huge freezer, filled with all sorts of interesting things. Have all three security guards triple team the two zombies at the freezer door (start shooting if the zombies get too close) and open the door (by pressing the nearby lever). Use the nearby health station if you want, and then go through the freezer. Take a left and keep going straight, past two doorways.
The guards will kill any headcrabs that come by, so don't worry about them. What you do have to worry about is the Bullsquid chasing the scientist. Gun down the Bullsquid (the guards will help too), and go into room the Bullsquid came from. Collect the grenades and pistol clips near the bodies, and take a left from the entrance of this room. Walk all the way down, and a Bullsquid will pop out from some nearby crates. Kill the Bullsquid quickly, and then press the red lever that's nearby. This lever activates the lift up above you. Grab the clips off of the dead security guard next to the lever, and retrace your steps all the way back to the freezer entrance. The security guards cannot go any further, so just have them wait there.
Climb the gray ladder near the freezer entrance and smash the grate. Crouch jump through the shaft and keep going. Smash the next grate nearby and kill the headcrab inside it. Follow the passage until you reach the lift you activated. Wait until it comes near you, and then jump on it. Smash each small crate for three batteries, and jump to the next vent shaft entrance when the lift is near it.
