The animals anger will vary with how hungry and tired they are, as well as other things. IGN said that the game, while similar to Far Cry, will have more wildlife, and that the way animals act in the game is as important to them as the humans. GSC Game World talked about the game's AI in January 2005. Some phrases used in the game ('The Zone', 'Stalker') as well as the idea of the game, are borrowed from the popular science fiction book Roadside Picnic by Boris and Arkady Strugatsky and the 1979 film Stalker, based on the book. The game includes features of role-playing and economic games. The game has a storyline that lets the player have a lot of freedom, and features gameplay features such as trading and two-way communication with NPCs. It features an alternate reality theme, where the second nuclear disaster happens at the Chernobyl Nuclear Power Plant in the near future and makes strange changes happen to the area around it, which create a lot of mutated animals, plants, and change the laws of Physics. The game uses a software feature called the 'X-Ray engine'.
S.T.A.L.K.E.R.: Shadow of Chernobyl, previously known as S.T.A.L.K.E.R.: Oblivion Lost, is a post-apocalyptic first-person shooter video game by Ukrainian developer GSC Game World.
