The game was publicly announced first at Tokyo Game Show 2005, under the slogan of "No Place to Hide".
Hideo Kojima wished to implement a new style of gameplay which was set in a full scale war zone. Kojima wanted to also keep the stealth elements in the game, which made the team abandon the "No Place to Hide" concept. The only announced war zone before release was the Middle East. Using several locations emphasized Kojima's original intention to portray the world in full scale conflict.
During development, the game's exclusivity was continuously questioned, even after Kojima officially confirmed the exclusivity several times. The exclusivity of this game is still questioned, months after the initial release.
The team had to make several compromises on the original story, to end the series, such as Sunny Gurlukovich and Dr. Clark were presumably male rather than MGS4 explaining them being female. The team also had to make compromises on the gameplay, such as removing some of the motion sensitive functions originally intended to be used.
Hideo Kojima announced that he would be retiring as director of the Metal Gear series after Metal Gear Solid 3: Snake Eater, and would leave his position open to another person for Metal Gear Solid 4. As a joke, the new director was announced as "Alan Smithee", but in R, a 400-page book bundled with Metal Gear Solid 3's Japanese "Premium Package", the director was revealed to be Shuyo Murata, co-writer of MGS3 and director of Zone of the Enders: The 2nd Runner. He has also contributed humorous Easter eggs to Metal Gear Solid 2: Sons of Liberty and Metal Gear: Ghost Babel. However, it was announced that Kojima would be co-directing the game with Murata after substantial negative fan reaction, including death threats.
The title was described as "essentially finished" by January 2008, and went through extensive beta testing. At Destination PlayStation on February 26, 2008, Sony announced that MGS4 would be released worldwide on June 12, 2008, along with the special MGS4 PlayStation 3 bundle.
