Very violent and gory.
Blood and body bits can be seen spraying out of enemies; it's possible to decapitate or dismember with blades and claws; and Aliens can even put an enemy's head into its mouth to crush it.
Some of the violence is seen in cinematic cut-scene sequences and/or in slow motion for dramatic effect.
In many cases, human and alien creatures scream out in pain.
As a marine, players use machine guns, sniper rifles, pistols, flamethrowers, and explosives to shoot and kill hostile enemies; the combat is frenetic and the blood splatter is fantastical-green or acidic acid emitting from the creatures.
The Alien and Predator attacks represent the most intense aspects of violence: wrist-blades are used to pierce through eyes, rip off heads; an Alien's inner mouth can smash through human skulls; a baby alien will burst out of the chest of a human host's body; heads and human spines are torn out (shown close-up) then gently caressed blood dripping from the spinal column.
Heads can be ripped from bodies, and there are clouds of blood visible as marines or other human characters are evaporated in laser fire. It is also possible for the player to inflict post-mortem damage on enemies - the Alien's tail, for example, can sever limbs or heads from torsos, or the player can activate the second set of teeth of the Alien, so you can force your teeth through an enemy's head. This is shown with a rapid zoom into the victim and an accompanying cloud of blood - as the camera pulls back we clearly see a gaping hole in the victim's head, with teeth exposed or the bloody eye socket and / or puncture wound visible.
The player is also able to use a gory 'grab' move by pressing one button, which produces different results - for example we see the Alien's claws pierce the eye sockets and mouth of a human before ripping off his head in one move, while another results in a very quick pierce of the forehead with the tip of the Alien's tail.
When playing as the Predator, attacks include sight of human heads and spinal cords being pulled out, usually with a look of wide-eyed horror on the faces of the human victims.
There is a lot of bloodshed in this game, from aliens, predators, humans, and androids. Those who have seen the Alien movies will know that the aliens bleed acid, which can hurt the player if splashed by it.
Some bodies eventually disappear after death, and some enemies can be dismembered.
Aliens can explode when incinerated with a flamethrower.
During the Marines campaign, there are some skinned human corpses hanging from above.
An alien bursts out of a man's chest.
One cutscene has an android shot in the head.
The Predator player can choose to rip out human heads and spines in gruesome detail.
When playing as alien, you can kill enemies with your claws or tail. Finishing moves include biting heads off from a visceral first-person perspective, decapitations, harvesting prey with a facehugger, or skewering enemies with your tail.
The beginning of the Aliens campaign features some human test subjects being hosted for Alien larvae. The scenes are very violent and disturbing.
At the end of the Alien campaign, the alien removes the Elite Predators mask from his face and attaches a facehugger to him, in up-close detail. Later on, a xenomorph transforms into an Alien queen, with her new self bursting out of her old shell. Her chamber is surrounded with half-dead human hosts.
During the Predator mission, the player can slice through opponents, blast them into gory chunks with arc cannons, and unleash gory finishing moves like ripping an alien's tongue out, impaling heads, breaking (or ripping out) spines, decapitations, slitting throats, and impalings.
Predator can take trophies from the humans, such as ripping out their head and spine in gruesome detail.
Sometimes, you have to use a decapitated head to access retinal scanners, which I found incredibly revolting.
A Predalien (Predator/Alien hybrid) rips out a human's spine off screen, but we see the bloody trophy in the creature's hand a second later.
In the Marines campaign, a Predator rips out a Marines head and spine in gory detail.
People and aliens blown apart, heads cut off and spines ripped out, lots of blood and gore and detail.