F.E.A.R. Codes -

Unlock All Levels
Enter "F3ARDAY1" as your profile name to unlock all levels (note that achievements will be disabled).

Achievements
Do the following tasks to unlock the following achievements and thier alloted gamerscore:

Ammo Hog (35) - Win the Campaign using less than 500 rounds of ammo.
Armacham (5) - Complete Interval 7 in the Campaign.
Assaulter (5) - Kill 50 enemies with the G2A2 in any ranked Multiplayer games.
Belly Gunner (5) - Kill 50 enemies with the turret in any ranked Multiplayer games.
Black Belt (5) - Kill 50 enemies with Round House Kicks, Flying Kicks, or Slide Tackles in any ranked MP games.
Brawler (5) - Kill 50 enemies with Punches or Rifle Butts in any ranked Multiplayer games.
Bullet Sponge (5) - Use 50 armor vests in the Campaign or Instant Action.
Dead Eye (35) - Kill 150 enemies with Headshots in any ranked Multiplayer games.
Demolitions Expert (35) - Kill 200 enemies with the N6A3, AT-S or M77 in any ranked Multiplayer games.
Disintegrator (5) - Kill 50 enemies with the Type-7 in any ranked Multiplayer games.
Dual Machinist (5) - Kill 50 enemies with the SM15 in any ranked Multiplayer games.
Environmentalist (5) - Kill 10 enemies with barrels, fire extinguishers or fuse boxes in the Campaign or Instant Action.
Explorer (35) - Find every Health Booster and Reflex Booster in the single player campaign.
Explosives Expert (5) - Kill 3 or more enemies with a single N6A3, AT-S or M77 in the Campaign or Instant Action.
Exterminator (35) - Kill every enemy in the Campaign.
Feared (5) - Complete every Instant Action map on any difficulty except Low.
Fearless (35) - Win the Campaign on any difficulty except Low.
Fearless Flagman (75) - Successfully capture 50 flags in ranked CTF or SlowMo CTF games.
Fearsome (100) - Complete the Campaign on Extreme difficulty.
Grenadier (5) - Kill 50 enemies with the N6A3 in any ranked Multiplayer games.
Initiation (5) - Complete Interval 2 in the Campaign.
Intel (5) - Gather every phone message and lap top in the Campaign.
Medic! (5) - Use 50 Medkits in the Campaign or Instant Action.
MP 100 (5) - Participate in 100 rank Multiplayer games of any type.
MP 1000 (75) - Participate in 1000 ranked Multiplayer games of any type.
Multiplayer Victory (75) - Win any ranked Deathmatch, SlowMo Deathmatch, or Elimination Multiplayer game.
No Fear (35) - Win every Instant Action map on Extreme difficulty.
No Juice (65) - Complete the Campaign on any difficulty without using any boosters.
Perforator (5) - Kill 50 enemies with the 10mm HV Penetrator in any ranked Multiplayer games.
Pistoleer (5) - Kill 50 enemies with the AT-14 in any ranked Multiplayer games.
PumpShotty Ownage (5) - Kill 50 enemies with the VK-12 in any ranked Multiplayer games.
Real Time (65) - Complete the Campaign on any difficulty without using SlowMo.
Repeating Offender (5) - Kill 50 enemies with the MP-50 in any ranked Multiplayer games.
Rocketman (5) - Kill 50 enemies with the MOD-3 in any ranked Multiplayer games.
Sapper (5) - Kill 50 enemies with the M77 in any ranked Multiplayer games.
Secret Facility (5) - Complete Interval 10 in the Campaign.
Slow Jo (5) - Kill 5 enemies with one SlowMo use in the Campaign or Instant Action.
Slums (5) - Complete Interval 8 in the Campaign.
Sniper (5) - Kill 50 enemies with the ASP in any ranked Multiplayer games.
Sub-Jugator (5) - Kill 50 enemies with the RPL in any ranked Multiplayer games.
Survivalist (150) - Complete the Campaign on any difficulty without dying.
Team Victory (5) - Win 5 each of ranked CTF, SlowMo CTF, TDM, SlowMo TDM, and Team Elimination games in Multiplayer.
Trap Layer (5) - Kill 50 enemies with the AT-S in any ranked Multiplayer games.
Water Treatment Facility (5) - Complete Interval 3 in the Campaign.

Save Your Medkits
Note every medkit you cannot carry -- if you happen to run out of your medkit supplies you can find them again. This is useful in Interval 11 with the armies of ghosts coming after you. Just make sure that you are able to backtrack to get the Medkits you left behind. Use your Medkits at the correct time. Do not use Medkits immediately when you have about 70 to 80 health remaining. Try using a Medkit when your health drops below 30. One Medkit can heal up to about 30 to 45 points. If your health happens to drop below 40 and you are in a 1v1 or 2v1 fight, do not bother using a Medkit unless you really need to. Just run to cover while using your slow-mo abilities. Your health will regenerate slowly back to 40 if it drops below that, however you must be out of the firefight to regenerate your health.

Interval 04: Office Space reference
While making your way through the large office building, look for papers hung on the wall or scattered on desks. Many of these papers have "TPS Report" written on them, as well as a symbol including three boxes at the top. This is a reference to the popular movie Office Space in which the characters are involved with TPS reports at their office, Initech, which has almost the same logo as the symbol at the top of the papers. As you are making your way through the large office building, about midway through the level there should be a large room filled with cubicles, with multiple offices on the side. One of the cubicles in the middle of the room has a lot of boxes piled into it, with a red stapler on the desk. This is in reference to the character Milton in Office Space. Management is always making him move his desk and using his area for storage, as well as stealing his red Swingline stapler. This can be found in the same area as multiple T.P.S. reports.

Glitch: Unlimited Handgun Ammunition
This trick requires the dual handguns, all weapon slots full and at least one bullet for the dual handguns. Have the dual hand guns equipped and find a weapon you do not have in your inventory. This weapon must be on the floor, not leaning or on top of something. Hold Square to switch out the dual handguns for the new weapon, then switch back for one handgun then grab the other. You will notice that you have more handgun ammo. For example, if you had 1 bullet for both and you used this trick you should now have 2 bullets. If you repeat the trick, it will increase to 4 then 8, 16, 32, 64, 128 then the maximum of 200.