The gameplay focuses on raising alien creatures known as Norns, teaching them to survive, helping them explore their world, defending them against other species, and breeding them.

Rather than taking a scripted approach, the games in the Creatures series were driven by detailed biological and neurological simulation and its unexpected results.

The program was one of the first commercial titles[1] to code artificial life organisms from the genetic level upwards using a sophisticated biochemistry and neural network brains,[2][3] including simulated senses of sight, hearing and touch.

[8] Dickinson and Balleine state that while this stimulus-response/reinforcement process makes the creatures seem like they are goal-directed, they are instead 'habit machines' responding in a learned fashion to particular stimuli.

[9] Mutations in the genome can occur, allowing new characteristics to appear in the population and potentially be inherited by a future generation.

[10][11] Because the Norns have a lifespan of roughly 40 hours, users could observe the changes that occur over a large number of generations.

Among the fans of Creatures were the Oxford zoologist Richard Dawkins, who called it a "quantum leap in the development of artificial life",[21] and author Douglas Adams.

[32][33] Based on sales of 500,000 copies of Creatures from 1996 through to the second quarter of 1998, it was estimated that at that time, there was a possible global population of up to five million norns.

[34] In 1998, the video games division of Millennium was sold to Sony Entertainment while those working on alife and Creatures formed a new company called Cyberlife Technology.

[41][42] The final major Creatures release, Docking Station, was made available for download from the company's web site in 2001.

[44] Gameware staff that previously worked on Creatures developed a convergent media game for the BBC called BAMZOOKi.

The original Creatures game, released in the United Kingdom and Australia in November 1996 and in North America in July 1997, took place on the fictional disc-shaped world Albia.

New technology and species were made available to the player, and the creatures themselves had been provided with "considerably more sensory input, more actions they can take, and improved brain dynamics".

[77] Released in 2000, and targeted at younger children (ages 6–9), Creatures Adventures dropped the complex interface of the main series in favour of brighter graphics and a more childlike atmosphere.

[78] The second game in the younger children's series, Creatures Playground (released the same year), could be connected to Adventures to create an even bigger world to explore.

[82] Creatures Online was to have 5 worlds, was to be completely in 3D instead of 2.5D[8] pre-rendered graphics, and in-game currency was planned to buy Norns toys, food, etc.

It was intended as a successor to Creatures Online, with a target audience over 20 years old, but was quietly canceled for "technical reasons" sometime before August 2019.

Creatures 3 and Docking Station plus a selection of new Norn breeds on one disk, updated for improved Windows XP compatibility.

[94] (For Creatures Village, aimed at very young players, tickling is done by a feather wand, and punishment is represented by a squirt bottle.

[4] Some alternate play styles include "wolfling runs", where the player may not intervene in their creatures' lives,[72] or even norn torture.

[105] Trying to selectively breed or engineer certain traits into the population is also popular, for example, coloured creatures, norns with a better immune system,[14][106] or a less-aggressive grendel.

A Norn is an AIL (Artificial intelligent life) species, the development and survival of which constitute the main thematic elements of the program.

From Creatures 2 onwards, Norns also possess organs determined by their genetics;[34] mutation and injury can render these defunct, with typically fatal consequences.

Norns are omnivores and eat a variety of foods, including carrots, lemons, seeds, insects, fish, honey, and other things.

C2 Ettins behave rather differently; they tend to lead a sad and lonely life underground with no one but Pitz and the occasional Grendel for company.

The backstory in the guides and manual, as well as the opening sequence, reveals that they once lived in the desert at the top of Albia and, true to their nature, built the pyramid that sits there.

[125] Eddie Walou praised the simplified user interface of Creatures 4, saying that earlier games felt like you had to have your BAC to understand.

[15] The backdrop for Creatures was created by taking photographs of a physical model of the world,[28] part of which is now housed at The Centre for Computing History.

[130] In Creatures 2, the environment became more complex, with a "Complete working eco-system, including weather, seasons and a functioning food-chain.

[145] Don Labriola, another game reviewer, wrote of Creatures that "no other program so successfully mirrors the joys and challenges of raising a child or pet.