Content review for this game:
Pertaining to the ESRB rating.

Blood and gore: The blood spurts and puffs in clouds and in moderate to heavy amounts when you hit or shoot an enemy. Blood does linger, splatters onto walls and floors; there is static blood smeared on walls and floors; and you often see blood dripping from ceilings, grates and vents. Bodies do linger, and you see many heavily bloodied civilian and allied unit bodies lying in pools of blood; groups of mysteriously incinerated and smoking skeletons lying in huge pools of blood; and you see many dead and bloodied bodies fall from ceilings, elevator shafts and balconies throughout. Addtionally, there is gibbing, meaning when you shoot an enemy with the Particle gun or shotgun (in close quarters), they will explode into large bloody chunks.

Limbs gradually get damaged with these weapons, and close-up shots often result in severing enemies from the waist, as well as dismembering them from the head, arms and legs, all causing the affected body parts to then squirt a moderate amount of blood--if Reflex mode is on, you'll see as they fly off in detailed slow-mo, and their limbs do linger. However, you can disable blood and gore for gameplay at any time by going into the pause menu, "Game Options," and then turn "Gore" off. This'll remove real-time blood, gibbing and dismemberment during gameplay, but all pre-existing blood on walls, floors and bodies and some splatter in cutscenes will remain.

Specific scenes of blood & gore:

(As a quick note, not only are the below scenes bloody and gory, but the majority of them are also very violent and contain many horrific and/or bizarre elements common to this genre).

The opening scene shows the mentally unstable Paxton Fettel sitting in his cell, having visions of Alma (a figurative little girl with psychic power, and the game's main villain) walking through fire towards him. She then apparently gives him an order, causing him to break from his cell, as he begins to psychically control the clone soldiers called Replica, which belong to the ATC company that is holding him. You then see as he walks up behind an ATC security guard and quickly slashes the guards jugular with a knife, resulting in heavy blood jetting from the guards neck, as it stains his and Fettel's clothes. It then cuts to several more shots of heavily bloodied and sliced apart security guards lying on the blood stained floors, and eventually cuts to Fettel's back view, as you see him feed on an ATC guard (no details are seen), with Fettel then slowly turning towards the camera, showing his blood-stained mouth.
While running through a corridor searching for Fettel, you see a brief and disturbing flash on screen, showing a man's heavily beaten and bloodied face. When you reach the targeted room, you find this man there, propped dead on a chair (his blood splatter all over the floors and walls), head back, with a heavily bloodied face and the majority of his skin missing on one side, giving a graphically detailed and grotesque view of his inner mouth, gums and teeth.
After opening a gate for you and your team, you slowly walk toward three smoking skeletons lying in a huge pool of blood. This prompts a flashback, showing your fellow soldiers as they run from Alma (who's walking with fire all around), as heavy amounts of blood continuously puffs from their bodies. She proceeds to get closer, causing the soldiers to burn in her flames, as they scream, blood flies and they start to disentegrate into bloodied skeletons.
While you continue to search the area for Fettel, Alma appears as you suddenly fall down a hatch, and then find yourself at the end of a dark, narrow hallway filled halfway with blood. As you slowly wade through it and reach the door at the end, a bloodied skeleton unexpectedly pops out from under the pool of blood and grabs you, making you snap out the vision and back into reality.
When you approach a door, you see as Alma quickly slam it in your face. You then find yourself in a long hallway again, only this time, the pool of blood is hanging upside down from the ceiling. As you slowly walk toward the door at the other end (which has fire burning behind), you hear a man help a screaming woman deliver a baby. When you reach the door, one of Alma's psychically projected Nightmares (that basically look like glowing-eyed corpses with no mouths) flies out toward you. You then turn around, as you see it disappears with Alma down the hall, and you snap out of the vision, into reality.
While you run toward your goal, you see another bloodied face flash on screen. when you reach the heavily bloodied body slumped over in a chair, the man's bloody head unexpectedly pulls back, he says something cryptic, and then dies.
As you enter from a door, and your team from the elevator, you find bloodied and smoking skeletons all over, with blood covering the room like paint.
Later on, Fettel takes a main character hostage, and to taunt you, he shows you a vision overlaid on a room's corner, revealing the character lying dead and bloodied, with his/her blood splattered all over the floors and walls.
When you go to activate an elevator, you abruptly find yourself in a vision, falling down its shaft into a deep pool of blood, full of skeletons, below. You then dive under and find an opening, as Alma slowly passes by it, her eyes fixated toward you. When you fall through it you find yourself in a dry hallway, walk up a set of stairs to a door, and then to the reoccurring hallway at the end. As you walk down this hall in slow-mo, and with vision blurred, you hear a woman scream, find yourself in darkness, fire all around, as Alma's Nightmares jump out at you from all directions--you then snap out it and back into reality.
Nearer the end, you see a main character shoot a reoccurring side character from a distance--when you reach him, you find him half dead in his blood.
While walking down a corridor, you see a vision of Fettel feeding on his hostage in the corner. Darkness surrounds you, but you then snap out of it, finding the vision to be real, as you're then made to shoot Fettel in the head. After the fact, you see blood splattered all over the floor and walls around the hostage's body.
As you reach a door and watch from behind its tempered window, a main character releases the supposed-dead Alma from her chamber. You soon see what appears to be the haggard, nude (more detail on this in "Partial nudity") Alma appear from nowhere, as she then uses her psychic powers to implode the culprit, causing the character's blood to cover the window and block your view. After this, you see a vision of her walking toward you, first as a girl, then as her real self, and as you snap out of it and walk into the room, you see the dead character's bloodied skeleton and blood splattered all over the walls and floors.
After catching up to Alma, you appear in a vision with a large room on fire. Alma jumps out at you and you shoot at her, resulting in her vanishing (and some blood splatter). You walk further, she attacks once more, and you find yourself in the hall again. You reach the end--and as you look through the window, you see Alma use her powers on a man behind it, making his heavy blood splatter block your view. Alma then sneaks behind you, you turn around and shoot her, causing her to vanish and you to snap back into reality.

Intense violence: You're put into the shoes of a newly joined F.E.A.R. (short for First Encounter Assault Recon) operative with psychic sensitivity and superhuman reflexes, who is recruited and then sent out to investigate and track down an escaped, unstable and failed experiment named Paxton Fettel. He's psychically controlling clone soldiers called Replica, by the psychic orders of the ATC's (short for the Armacham Technology Corporation) failed experiment, Alma Wade (a crazed and extremely powerful psychic girl), in order for her to take her revenge on the ATC. You'll have to fight through the cloned Replica, Alma's constant, disturbing psychic visions and the ATC's men, to find and ultimately eliminate Paxton Fettel, and stop this madness...

The base gameplay consists of you navigating the pitch-black and often maze-like environments with your flashlight, as you take constant detours around the blocked and barricaded paths/doors by climbing up and down ladders; jumping from platform to platform; crawling into windows, vents and grates; taking elevators; and swimming through water—all the while you clear out enemies with your guns and super reflexes, retrieve intel from laptops, deal with Alma's psychic attacks and scavenge for ammo, weapons, armor, med-kits and ability boosters in order to survive. You'll also perform some mild puzzle solving by using switches and valves to open gates; reactivate downed elevators; override security systems; rotate platforms and raise water to cross broken paths; and disable gas and electric hazards blocking your way.

Your enemy, at first, is made up of a variety of Fettel's psychically controlled Replica soldiers (basic grunts, the Assassins, Heavy and Power armor types); later in, the ATC's men, their security turrets and hovering UAV robotic sentry drones; and finally Alma's creepy, psychically projected Nightmares. You'll be combating these enemies with a couple of (dual) pistols, (dual) machine guns, assault rifles, grenades—frag, proximity (which explode when enemies get close) and remote bombs (throw at enemies, then detonate with switch)—a shotgun, sniper rifle, multi-rocket launcher, the HV Penetrator (or boltgun), the Type 7 Particle weapon (an incinerator), and the Repeating Cannon (which shoots large, cannon ball-like projectiles).

The combat system is hectic, thrilling and intense, with you shooting through enemies with your varied arsenal (as you see bullets tear through enemies in your slow-mo, heightened Reflex mode, while the dozens of shots kick up clouds of dust and debris, as bullet casings clink to the floor); use your many grenades and exploding objects to dispatch enemies nearby (causing bodies, dust and debris to fly); the Penetrator to shoot large metal bolts, which then fully impale and violently pin enemies and their limbs to nearby walls; the Type 7 Particle weapon to incinerate enemies down to the skeleton; and the butt of weapons and your melee attacks to beat them down.

When shot, Replica soldiers will, at first, fall from gunfire, get back up, limp slowly to cover when injured, and after they're finally downed, they'll scream (Heavy and Assassin types will growl in electronic tones) and fly back, as their final relex actions make them fire off shots and fall in contorted positions. Add this, the overwhelming odds (dozens of enemies against just you); environment's destructible nature (glass shatters; wood breaks apart; random objects fly off of shelves; bullets break away at and imbed themselves in walls, sparks and dust fly as your bullets tear at the area, etc.) and their disheveled appearance (once public buildings are messily overturned, their doors are barricaded by random furniture and boarded up, walls are newly ridden by bullets, etc.), it gives combat a jarring, tense and chaotic feel.

Because of environments' wide open and exposed nature, enemy encounters give a strong sense of insecurity and unsuredness--you never know what direction they'll come from next. And when encountered, enemies will start to converse rapidly on their radios in gravelly voices, as they gather and then rush you in large groups, rappel from glass sunroofs and helicopters, pile out of the back of large vans (which near the end, try to run you down in alleys only wide enough for their vans, making you dodge through side openings or backtrack in slow-mo before they run right over you), as they proceed to flank you, put heavy fire on your position, (later on) snipe you from afar with the incinerating Particle guns (which kills in two hits), fling grenades your way, and bash at you with their melee attacks in close quarters...

It only gets more chaotic later on, as you encounter the more powerful mini-boss Heavy (in suits that take six times the damage, are armed with rocket launchers, Penetrator and Particle guns, and rush you in close quarters), Power (encased in mech suits that take twelve times the damage, barrage you with dozens of missiles and attack with their huge mech arms) and Assassins Replica types (who are extremely fast and jump from wall to wall, as they use stealth camo to disappear, reappear, rush, and then slash at you close up). And nearer the end, the ATC's security turrets will descend out of ceilings and start shooting at you with high-powered machine guns from the other end of rooms, and the ATC's UAV hovering drones will break through windows unexpectedly, attacking with lasers—enemies don't mess around.

When you're not fighting the enemy, you'll have to deal with Alma's hauntings; as you walk through the lonely, ruined, dark and abandoned corridors, random objects will shake off shelves and fly toward you; doors slam in your face, blocking your way; lights flicker and blow out; figures eerily pass by doorways and the corner of your eyes, as they disappear into ashes; and strange, static sounds play over your radio as unexpected voices (or screams) echo out in the dark, all the while appropriately eerie and tense music plays, while Alma laughs and (later on) sics her deadly Nightmares (glowing eyed, mouthless corpses) from pockets of psychic energy, as they fly out quickly and attack. And since you're always alone, it gives a great sense of fear, isolation, vulnerability, and foreboding—Alma is everywhere and she is in control.

The cutscenes contain a few chaotic explosions; near the end, your helicopter is downed, injuring two of your teammates; a few of the main characters die; and Alma continues to play mind games with you in the form of cryptic flashbacks and creepy psychic vision. When it comes to age, this is not for younger teens; although the language is far and few between, it's still strong and prevalent; there may be an option to turn off some gore in combat, but even with it disabled, it leaves tons of blood splattered and smeared in the environments; and as this is a horror game, the encounters with Alma are disturbing, gory and bizarre, and the story is appropriately sick, twisted and somewhat tragic—it's just more suited to older teens and adults.

Strong language: There are (including the optional answering machine messages) over two dozen uses of the f-word, over a dozen uses of sh*t, under a dozen uses of hell and a**, three or under uses of SoB, b*tch, God and God d*mn, and one use of d*mn, bastard, God and Christ. Other than the main script, enemies will frequently use the f-word and sh*t during gunfights. There is no option to turn language off.

Partial Nudity: (The ESRB didn't mention this in their rating) Near the very end, Alma appears in her adult form, nude. But, even though (in a few shots) you can see the overall outline of her behind, breasts and what appears to be pubic hair, her long black, matted hair covers the majority of her body (meaning you see no real detail), and she looks haggard, lifeless and gaunt—she is in no way appealing.