DO NOT READ THIS ! 
(unless you are Stuck in a particular area of the game)

Level 1 (Learning Curve)
Do not press the self-destruct button, located on the desk, right away.  You need to gather the weapons first (located on the 3 desks inside the cargo bay area).  Then, let the grunts out of the containments (one at a time) by pressing the button located on each desk.  Until you find the HEV suit located in level 2a, you can change/select weapons by pressing “Weapon cycle Selection Key” on the keyboard.  This key is the right bracket or ” ] “, you can also reload a weapon by pressing the “R” key.  Once you have collected all the grunts weapons, you should now go back to the ship’s cabin and press the self-destruct button.  You will hear the count-down begin.  The bay door will open, where a ITR is activated and ready to teleport you down to Earth’s surface, within the Black Mesa complex.

Level 2 (Abandoned)
You find yourself in a small shed with radio activity everywhere execpt along the concrete walkway.
The ITR has activated it’s Time Node, a yellow globe of light.  It is located outside.  Break the rusted collapsing door with your crowbar and walk into the time node.  To be ready for what may be waiting for you in the new time line, it is wise to turn around and walk backwards into the time node so you are not facing the concrete wall when time traveling into the Past.

Level 2a (Same area as above, but 40 years in the past)
Run, deal with the grunt on the other side of the fence and collect his ARgrenades.  Walk towards the door of the shed, when the door opens,  there are 2 grunts working in there.  Begin to run backwards and fire a ARgrenade into the shed angled to the right.  Collect their weapons and ammo.  Break all the boxes in the shed and especially along side the elevator.  The HEV is located in one of the tall crates.  Use the elevator.  Position yourself to the rear of the elevator and crouch down so the grunts can’t see or shoot at you very well.  Ignore them if you can.  Look down through the floor of the elevator, you will see that the grunts have placed trip mines at the bottom of the elevator shaft.  Jump off the elevator (near the bottom) into the last fire exit doorway.  Move as close to the fire door as possible to avoid getting hit with debris from the explosion.  There are some boxes there.  Break them open.  Jump down into the elevator debris at the bottom of the shaft.  Walk down the long hallway, which le
vel changes to Level 2b. There is a grunt and ceiling mounted turret at the end of the hall.  Walk to the end and let the grunt see you, then quickly walk backwards along the lefthand side of the wall as soon as the grunt enters the hallway blast him with a ARgrenade.  Listen and wait for the ceiling turret to shut down, then quickly run up to it and let it eat some bullets.  There is a first-aid-kit located in the booth in the dark shadows.

Level 2b (Warehouse)
Open the door and walk up to the boxes.  There are 2 grunts down below working.  Don’t let them see you.  Launch one ARgrenade and they are history.  There is 1 more grunt along the back wall who generally runs to hide in the right corner where it is dark.  Jump down into the warehouse and collect the dead grunts weapons/ammo.  Position yourself to the back right set of stairs and let loose an ARgrenade into the corner of the building (dark shadow area).  That grunt is history.  Ignore all the boxes in this warehouse as they are empty.  Shoot the explosive crate located on  the loading dock to break open the white bay door.  Go into this room with the rods and green glowing lights.  Don’t touch the 2 humming machines, they are electrified.  Go up the stairs and do a crouch jump to make it over the hand rail and humming maching on the right hand side.  You may land short and touch the end of the machine, but it won’t kill you.  Turn on your Flashlight.  There is a door that leads to a hallway with steel mesh f
loor.  Barrels containing explosive material is kept here.  Slowly walk towards the door you see at the end of the hallway.  An explosion will rip the floor apart.  Carefully, walk along the top of this pipe under the floor area.  If you slip off you die.  There is a battery located at the end of this pipe.  The door here is locked.  Go back to the dark shadow area of the electric room.  Use flashlight to see ventilation grill on right hand side of wall.  Move 1 small box from left side to right side and jump up the boxes to reach ventilation ductwork.  Go inside vent and make your way to the next guard booth area.  Two grunts and another ceiling turret wait for you there.  Use the first-aid and suit recharger there.  Use elevator to go to level 3.

Level 3 (Night Walk)
Red bay door opens.  Walk forward, see the cargo container with the open doors to your immediate right.  It is filled with boxes containing weapons and goodies.  Break boxes.  Use crossbow to take out the first 2 grunts standing by heli-pad in wide open.  If one sees you, he will notify all the other grunts and you will have your hands full.  Quickly run inside the cargo container and pick off grunts as they walk in front of you.  The safest place to be is inside the cargo container.  After dealing with the grunts, step over the pile of bodies and collect their weapons/ammo.  One more grunt is in the concrete bunker, use flashlight and crossbow to take him out.  Go into bunker and press the security button located there.  This will open up the stainless steel door, which leads to the elevator and level 4.  For fun and before using this door, use the red bay door and take the rusted cargo elevator down.  Autosaves are there.

Level 4 (Junction)
Get off the elevator and break open the boxes of goodies.  Ignore the poor worker who is too scared to speak or respond to you.  You can deal with this area using a new strategy.  Use the missle launcher.  Turn off the laser guided beam, as you don’t want to stand there and guide a missle.  Open door and fire a missle towards the far wall and in between the grunts, this way you can take out 2 grunts at a time. Important, the strategy here is to open door, fire and quickly run backwards away from door before their ARgrenades can reach you from above.  This works well and you should be able to get most of the grunts with the missle launcher.. Use machine gun for the rest.  Recharge your health and suit as required.  There will be one grunt high above that will kill you if you don’t take him out before using the teleporter.  When safe, go into big room and use the first plat on your left hand side to take you to the teleport booth.  New area.  Don’t kill any of the scientists here, just watch them and move on.  
At the end of the hallway, take the stairs up and join the party.  If you are low on heath, ask a scientist to heal you.  There is also a health-kit in a box in one of the rooms.  When the music is almost over, Two grunts will burst throught the wall and kill all the scientists.  You can run away and forget about it or take on the 2 grunts.  Go back to teleporter and find the plat that goes up to the only door located high above.  This door leads to Level 5.

Level 5 (Meat Grinder)
There are 4 grunts here.  Two on the deck where meat grinder is located (the door there is locked). Another grunt is between the truck and body parts/fluid tank.  One grunt is under the metal deck down below you.  At the bottom is a locked red bay door.  To the left of it is a ventilation duct blocked by a steel barrel.  Break the barrel with crowbar or blow it up.  Vent leads to level 6.

Level 6 (Duct Out)
Take out the grunt at the far end of this area near door.  This area will test your ability to see depth perception and semi-junping skills.  Only 2 areas require actual jumps, the rest are best completed by just walking toward the ductwork located below.  Use the mouse look and movement keys to guide yourself onto the ducts located below.  You should “quick save” F6 here often.  When you are about 1/2 way down or a little more, it is time to pick off grunts located below.  If you wait too long they will pick you off.  Use distance weapons ie: handgrenades, crossbow,  ARgrenades and machine gun.  Don’t jump onto the boiler located in the corner or you will die.  Rechargers and boxes are presented in the opposite corner of this room.  Use the plat to go up to the only door in this room.  The hallway has two locked doors and an elevator to level 7.

Level 7 (Grunt-Atorium)
The elevator leads to the surface.  There is a short hallway with a grunt behind boxes who may or may not take you on.  Past the bay door is another short hallway, push and use the barrels there to position yourself near the end of the hallway to the outside area.  Crouch down and push the left barrel, when close enough aim 45 degrees up, then stand up and fire ARgrenade at grunt and sentry behind the sandbags.  Crouch back down and push barrel farther out.  Watch out as a grunt will try to walk around on the ground and get you.  There are 3 grunts on the roof, 2 left and 1 on the right.  One more grunt and sentry are located to the left behind sand bags.  Use the other barrel and push/crouch forward until you are in position.  Again, aim high at 45 degrees and stand up, let loose an ARgrenade and they are history.  Enter the building and take plat located on left at the end of the hallway.  This leads to the girls and a grunt getting his belt tightened.  Back down, go into the cafe area, a grunt with shotgun
 may or may not be there, (they move around) go down the hall open door straight ahead where game room is (grunt hiding in right hand corner.  Admire the nice pictures on walls.  To the right is a hallway, take the plat up there is a first-aid room with a doctor there for you.  Back down, take the door on the right to outside.  Do some target practise with Barney and in the storage room see the grunt getting his belt tighten as well.  The lower canal button opens a sliding hatch door, take the ladder down walk along and take the ladder up to level 8.

Level 8 (Fresh Air)
Shoot the signs out with shotgun, there are land mines here.  Run toward dead Barney and collect shotgun and shells.  There are 2 grunts and 2 sentries here. Position yourself to the far end of the big rock and shoot downward a land mine will go off.  Throw a handgrenade upwards against rockface   where grunt and sentry are.  Use crossbow to take out the other grunt and sentry.  Crouch down and edge your way along bottom of big rock.  You must be quick, if sentry sees you, you will probably die.  Alternate strategy is to use ARgrenade aimed high 45 degrees or hand grenades.  There are numerous fighting strategies that could be used here, some better than others. Use F6 to save and shotgun to blast in front of you to set off landmines.  There are first-aid kits here and ammo.  In the far corner is another canal hole in the ground, jump down and go into narrow pipe, which leads to level 8a.

Level 8a (A Drop In the Bucket)
Use flashlight and follow pipe to a small concrete joint.  Here you will find a mysterious dead dude in an HEV together with rocket launcher ammo and hand grenades.  The first clue to the Fuse Bar problem is presented here, written in blood on the wall.  Use rocket launcher with laser guide to take out the helicopter.  Two laser guided shots (if you are using medium skill level) will take out the chopper.  below are 2 grunts, use hand grenade to get both of them before the see you.  Use the two health kits located on the first concreate deck area.  If your health is too low ie: less than 75 it is doubtful you will survive this level and will not be able to proceed to other levels.  Anyway, use ARgrenade to get the grunt on right hand side below you.  He will start shooting ARgrenades at you if he sees you, this makes it very hard.  Take out the other grunt farther down with ARgrenades before you jump down to the first concrete deck.  When jumping down, use mouse look and direction keys to guide your fall dire
ctly onto the health kit.  As soon as you hit the concrete a repelling grunt begins his decent down a rope, quickly run over and ARgrenade him before he gets down or soon after, as he will start shooting ARgrenades at you right away.  Then jump again onto deck below, use the first-aid kit and make the final short jump down to ground below.   Enter the concrete room down there.  There is a health and suit re-charger down there.  Jump down through the access hole, which leads to level 8b.

Level 8b (A Leap of Faith)
This is just here to let you experience the feeling of falling from a great height and adds to the overall feeling of the game.  It was initially placed here to let the player know that he/she is going way down farther and farther underground.  I can’t remember which ones are dry and which have water to break your fall.  There are autosaves and auto reloads, so just try one after another until you get it right.  When you reach the end of this level, there is a teleporter to take you to level 9.

Level 9 (Water Cooler)
You need to change your strategy here.  You are about 3/4 finished the game and I want to challenge you even more.  You don’t always want to stay in an area and fight every last grunt do you?  Run like hell in this level.  Use the Barneys to help you at first.  Recruit 2 of them at a time and send them in ahead of you!  When you are tired of directing Barneys or they are all dead, it’s your turn to go in and face the heat.  There are plenty of health/suit chargers here, so do go back and recharge when you get low, then press F6 to keep your progress.   If you find the back entrance to the where the truck is, clean out this area first use ARgrenades on sentries and grunts.  With these guys out of the way your next step is easier. There is a health/suit recharger here.  Watch your back while using these rechargers.   Note: This level is not easy and you will have to move, fight hard and run like hell here in order to survive.    You may want to F6 “quick save when you make a little ground and make that little p
rogress.  There is a desk there with the security pass on it.  Run down jump on the desk to get card, immediately turn around and blast anything in your way with ARgrenades, then run like hell to the locked security door nearby on your left at this point. Once you clear the security pass locked door, take the hallway to the end and teleport to level 9a. This is one of the hardest levels in the game, if you make it this far and get through this level, you really have accomplished something.

Level 9a (Times Up)
Time to relax and recoup from last level.  You teleport into what seems to be a maintence area with Test Labs to the left.  Security Card access door on the right is not really a maint. access to generator.  Door straight ahead is locked-out.  Barney guards door on left.  Shoot Barney in the head.  Proceed down to the smart mouth Barneys and shoot them in the head twice.  Don’t bother the scientists in the rooms along this hallway.  Take the plat down to get the first security card, which is used to open the Generator Maint. door.  Shoot Einstein in the head to complete your mission.  Take the weapons there and the security card on the desk in front of Einstein.  Go to the end of the hall and open “Authorized Personnel” locked door with the second security card.  G-man appears to see who you are and what you are doing.  The second clue to the Fuse Bar problem is presented here.  Look down at the floor.  Written in blood by the mystereous man in the HEV suit is 2....4...., which is the sequence to the fuse bar
s.  Shoot out fuse bar number two in the first set.  Shoot out fuse bar number 4 of the second set and finally, shoot out fuse bar number 2 of the last set.  A panel will open near the dead grunt.  Take the security card out of this unit, which is used to access the elevator to go to level 10.  You have 20 seconds to get out and on the elevator.

Level 10 (Lets go Home)
The elevator doors open and you see poor Barney fighting it out with some grunts at the top of the stairs.  You will have to be careful here.  go up the stairs while crouching and try to take out the sentry and grunt straight ahead of you.  Use the Gauss gun on them or crossbow if you have and bolts left.  Now comes the tricky part.  Let the grunts see you, but quickly run back down the stairs and hide behind the elevator wall so that you can just poke your gun out on the left hand side of the elevator.  This protects you and lets you pick off grunts as they come to the top of the stairs. Not all will come and you may have to go back an lure more of them to come after you.  Once they are smoked, use the health/suit rechargers at either end of the building.  Now ease your position and view outwards from either end where the chargers are.  There is an upper level, use ARgrenades to smoke the dudes up there. Once they are history there is 2-3 grunts left, one at each end of the hallways. Chew them up and then co
llect all weapons and ammo as you will need it big time for what’s coming up.  Ok, if it was not already activated from all the gun fire and ARgrenade blasts, you will need to activate the Time Node on the ITR.  Select the Glock pistol and place a single shot at the 3:00 o’clock position of the ITR, this will activate the yellow time node that you can jump through.  Go up the stairs and jump over the handrail into the time node.  This takes you back to the future or the current time line and loads level 11.

Level 11 (Current Timeline)
This level map is just to show you that you have made it back to the current timeline, where the Mesa Complex has been abandoned.  There is a rat there to greet you.  But wait, someone else has followed your movements.  The G-man is watching you and makes another appearance to learn the true nature of these ITR’s (why they are not just 1960’s Hippy artwork after all).  You don’t really take much notice and wait till he’s gone before stepping into the portal.  Simply, walk through the ITR to use it’s teleport function, which takes you to your home planet of Paradise  Esidarap and brings you to level 12.

Level 12 (Welcome Home)
You are glad to be home safe and sound.  You see that there is a message waiting for you from the World Council Members.  Read the message and go to the Chambers to get your reward.
Shit !!  That bastard G-Man has followed you to your friggen homeworld and wants revenge on you and your whole helpless planet.  Who would have thought that aliens would just teleport to your planet instead of flying there in spaceships?  The whole “First Strike Defense System” is useless against this type of technology.  The Xen survivors are killing all the inhabitants of Esidarap like a hot knife through butter, as your people have no weapons and wouldn’t know how to use them if they did.  So much for taking a hot babe to your new planet as a reward.  You will be lucky if you will even live long enough to watch your people die.  The healing units on Esidarap never run out of juice, just step into one and go to 100% and then carry on. Use all those ARgrenades and what else you have left to defeat the Xen aliens..To end this level quickly, just run like hell to the far end past the rotating electric generators and out through the door straight ahead and slightly to the right.  One last Alien Grunt is guardin
g the ITR to stop you from escaping....

Level 13 (Credits)
Text credits and then an amusing part giving credit to models as if they were actors in a movie.  Visual credits are also presented here for the weapon, truck and Nude Model authors