Vision mode allows the player to see Marines very clearly, while it renders Aliens nearly invisible; the Alien vision works in reverse, making aliens appear clearly and Marines nearly invisible. Regular vision allows one to see the environment and other Predators better than the former two visions, making battles between two or all three species a tactical juggle to prioritize enemies based on their threat to the player. The Predator's gameplay is more based on stealth and tactics than the average first-person shooter. The player has to be aware of Aliens, which have the ability to see through a Predator's cloaking device, that may climb up a tree and attack from below as well as taking care not to reveal themselves to marines too early as the marines’ weaponry and numbers are more than a match for the Predator. For long-range weaponry, the Predator can use a shoulder-mounted plasma cannon in addition to a chakram-like disc and a combi stick (or throwing spear). For close-range combat, the Predator has four retractable wristblades on its arms. The wrist blades allow for the Predator to perform a "trophy kill", a nod to the movies in which the Predators take trophies, usually skulls, from their defeated enemies to show their prowess in the hunt. OXM labeled the trophy kill mechanic as "spectacularly violent" and it has been partially censored to avoid an Adults Only rating in the United States as it was "several measures more graphic" than any other recent games. There are several animations, one of which is a "terrified" marine dragged into the center of the screen by his or her throat, which the Predator then snaps effortlessly with the accompanying sound of "someone biting into raw celery". The neck broken, the Predator cuts the marine's head, a "sizeable portion" of the spinal cord following. Even after this, the marine is still alive for a short period of time, "gasping his last, with nothing but bloodied, glistening vertebral column beneath his chin." Jason Kingsley, the CEO of Rebellion, defended the brutality of the trophy-kill system, stating "This is obviously a game based on adult-rated movies, and we want to make sure it’s very clearly an adult-rated game. It's an issue for me; some computer games are for kids– we're not making a computer game here for anyone other than adults. That's very clear and within that context, I think the violence