Quantum Theory

Quantum Theory, (known in Japan as ) is a third-person shooter video game for the PlayStation 3 and Xbox 360. It is developed by Team Tachyon and published by Tecmo. The game was released in September 2010.

The game centers around two characters named Syd and Filena who must fight through a "living tower". The game features a cover system that constantly adds and removes cover due to the tower being active.

Gameplay
The gameplay mechanics are nearly identical to Gears of War, with the biggest difference being the inability to perform "swat turns" or automatically move from cover to cover. Players can fire their weapon from the hip or aim down the sights for more precision—or blindfire from cover. All enemies explode upon death and a successful headshot is rewarded by a slow motion close up view of the head exploding. There are no hand held grenades but Syd can throw Fillena as a projectile weapon, resulting in a stun, major damage or instant kill depending on the enemy type. Syd can use his guns as melee weapons. Syd's initial melee attack can also result in a follow up attack by Fillena. Some levels feature environments that can change dynamically, including moving platforms that Syd must hang on to or jump off of. Bosses make appearances throughout the campaign, requiring the player to identify and target their weak points.

Setting
Set in an organic sci-fi world, years have passed since a world war left the world in a catastrophic state, leaving only a few survivors. In a new community "Cocoon", life has been threatened by a black material called Erosion, creating a post-apocalyptic environment. Surviving humans recruit a militia to conquer the Erosion and set out to take down the "Living Tower". The main character, Syd, has only intentions to destroy the Tower. He meets Filena along the way, as they both ascend to the top in their search for answers. The tower is constantly eroding, and intensifies as the game progresses.

Story
Most of the story takes place within the tower, beginning with Syd and a woman named Nyx trying to escape the tower as it begins to fall apart. The fates of the two are not shown and the story flashes back to where Syd and other soldiers fight through destroyed city streets against the Diablosis as they make their way into the "living tower". A poisonous growth called "the erosion" lives there, and their mission is to destroy the tower along with the erosion. Syd's entire squad is wiped out but he manages to enter the tower.

Syd meets Fillena for the first time when he sees her fighting the Diablosis and comes to her aid. After dispatching the enemy the two engage in a Mexican stand-off, after which they go their separate ways in the tower. Fillena and Syd meet again later on and reveal to each other their opposing quests: Syd is out to destroy the tower while Fillena wants to save it from the erosion. The two battle to a stalemate as their fight is interrupted by the Diablosis, whom they must fight together in order to survive. The two agree to join forces for the time being. Fillena tells Syd that her father created the tower, while throughout the story a voice speaks through the loud speaker in the tower, providing context. Through a series of flashback levels Syd is shown as a rookie, donning a mask which is broken in a later flashback, resulting in the x-shaped scar on Syd's forehead.

Syd and Fillena belong to warring factions, the Gilskins and the Nosferatu, respectively. Syd and Fillena join together, but split up later on. Syd and Fillena meet up again, and Fillena discovers that she is not human, but the prototype of a new breed of humanoids that her father had engineered. She is also the missing component that would empower the Diablosis as they merge with the erosion. Syd and Fillena battle the main Diablosis, but the Diablosis eventually absorbs Fillena. Syd kills it and frees Fillena.

Fillena and Syd make their way up to the top floor of the tower before confronting the brain of the tower, which instructs Fillena to kill Syd. Fillena points her weapon at Syd only to change her mind at the last second and open fire on the brain. This causes the entire tower be destroyed. After the credits both Syd and Filena are seen going towards another tower.

Reception
Quantum Theory has so far received mostly negative reviews, with a Metacritic aggregate score of 38 for the Xbox 360 version, and 43 for the PlayStation 3 version.