Originally, the game was supposed to be developed for the PlayStation 3, but due to the long wait for PS3, the game was developed for the PlayStation 2 instead. From the outset, Snake Eater's director Hideo Kojima wished to drastically change the setting from previous games. He stated that the jungle setting is what both his development team, and the Metal Gear fans, wanted. However, he acknowledged that the elements of a jungle environment, such as the weather, landscape and wildlife, were features that would present problems during the game's development. Whereas in previous installments the player starts out close to, or even within, the enemy base, Kojima wished Snake Eater to be more realistic, with Snake starting out miles from civilization and having to work his way to the enemy encampment.
Kojima commented that the outside environment was very difficult to create. He explained that the reason previous games were primarily set indoors is because the current consoles were not powerful enough to portray a true jungle environment. In contrast with urban environments, the jungle does not have a flat surface. The protagonist in Snake Eater has to cross uneven terrain, including rocks, dirt mounds and treestumps. As a result, the collision engine used in previous installments could not be used, and a new one had to be built from scratch. Setting up the motion capture technology so players could walk over these mounds was a problem during development.
Kojima designed Snake Eater's boss battles to be totally different from those in previous Metal Gear games, or any other games. He said that the boss battle with sniper The End best represented free, open gameplay in the game. The battle takes place over a large area of dense jungle, and the player must search extensively for The End, who attacks over long range from an unknown position. This battle of attrition can last for hours, and contrasts with other boss fights in which the enemy is right in front of the player and in view the whole time. In addition, the player has the ability to both avoid this boss battle altogether by killing The End earlier in the game or to simply save the game, wait over a week's time, and reloading the game for The End to die of old age. Kojima commented that features like this do not appear in other games.
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