Alien Breed: Conflict

Alien Breed 3D II: The Killing Grounds is a first-person shooter in which the player guides their character—a lone space marine—across 16 levels, surviving an alien onslaught along the way. The player's character can run, jump, and look vertically. The player utilizes an arsenal of up to ten weapons; they begin the game with a double-barrelled shotgun, and the remainder must first be found and picked up, such as a blaster, a plasma cannon, grenade and rocket launchers, a rifle, mines, and a gun that fires lasers that bounce off walls. Robots armed with energy or submachine guns constitute the bulk of the enemies the player fights with those weapons, but they also include red hellish dogs (the only reappearance from Alien Breed 3D), stick figures, and one-eyed floating monsters.

Many of the enemies continue to be displayed as bitmaps, but some, such as the giant bee-like creature, are rendered as 3D models. The weapons the player carries are also now shown as 3D objects.

After surviving an alien invasion on the Osiris base and destroying it, Captain Reynolds's escape shuttle is rescued by an Earth space cruiser, the Indomitable, which then sets course for Earth. However, a massive alien spaceship, having detected the shuttle's distress signal, enters the Indomitable's area, docks the cruiser, and commences an attack, taking its crew hostage. Reynolds awakes in the Earth ship's medical bay, isolated from the attack, and soon discovers that he is forced to fight for his survival on his own again.

Reynolds descends to the alien craft through a shaft connecting the two ships, attempting to find the missing Indomitable crew. After a series of fights with the aliens, he comes across a teleporter serving as a transporter between the craft and a planet. He also realizes that he had been lured into their trap, like the marines on board the Indomitable, and finds he is left with no choice but to teleport to the planet and press on. While there, he determines he is inside an alien military compound, and discovers a computer terminal, through which he connects his mind to a vast network of alien minds represented as bright threads. He sees that the threads intertwine, but fail to join or exchange thoughts, and that a large mass had suffered damage, explaining his observation of the aliens' disorganisation.

Soon after the release of Alien Breed 3D in October 1995, in the wake of competitors to their first-person shooter, Team17's Martyn Brown commissioned a sequel that would feature improved graphics. The competitors supported a much higher resolution, "but not playability", as Brown saw it, and Andrew Clitheroe, the original Alien Breed 3D's programmer and game designer, returned with the same roles for the new project.

Under the direction of Brown, Team17 were aiming to create an Amiga title similar in technology and experience to Quake. According to the game's producer, Phil Quirke-Webster, the gameplay was changed to more resemble Heretic than Doom; the levels were to feature missions the player must complete, rather than have a strict shoot 'em up style. Clitheroe stated that he sought to implement all ideas cut out of Alien Breed 3D due to hardware limitations. One of these was the enemy AI, which was upgraded so that the aliens could "communicate with each other and operate in teams".

Alien Breed 3D II: The Killing Grounds was the top-selling Amiga game from August to September 1996, according to Germany-based software distributor GTI. As late as January 1997, it remained one of the top-selling games for the system.

Critics were divided on the appropriateness of the hardware requirements and the enemy artificial intelligence, but were united in their judgement that the 2-MB version ran smoothly but with rudimentary graphics and that the 4-MB version required an Amiga computer with heavily accelerated graphics. CU Amiga justified the requirements by pointing out that Team17 intended to create a definitive Doom-clone for Amiga and noting that Worms: The Director's Cut, another video game of Team17, required an AGA chipset. The magazine praised the level layout and the artificial intelligence, the latter of which had given the enemies "a sense of menace ... that has not been matched" by the enemies seen in the game's Amiga competitors. The enemies have been described as erratic and unwilling to die, and the level layout is said to emphasise the need to conserve ammunition and health for later levels and battles.