Metal Gear Solid: Integral was released for the Sony PlayStation in Japan in June of 1999. It was an expanded version of the original Metal Gear Solid, released in North America in October 1998 and Japan in September 1998. It featured the English voice actors with the option of Japanese subtitles.
It added various things to the game, such as alternate outfits – a new sneaking suit for Meryl and a red costume for Ninja. A "very easy" difficulty mode was added, which gave Snake an all-new weapon – an MP5 submachine gun with infinite ammo.
Other additional features included a codec frequency that you could call to hear commentary from the design team, an option for enemies to take different patrol routes, and a first-person view mode, which would become a more common element in the series, starting with Metal Gear Solid 2: Sons of Liberty.
Finally, users could download a minigame for the PocketStation – a Japan-exclusive PDA that Sony developed as a peripheral for the PlayStation.
The VR Disc that was included with Metal Gear Solid: Integral offered over 300 VR missions that ranged from conventional training – sneaking, fighting, shooting – to absurd minigames such as murder mysteries and battling giant soldiers. The disc also included various extras such as a trailer for Metal Gear Solid, preview artwork of Metal Gear RAY from Metal Gear Solid 2: Sons of Liberty, and a photoshoot mode, in which the player could take photos of Mei-Ling and Dr. Naomi Hunter.
While Metal Gear Solid: Integral was not released outside of Japan, variants of it were released in North America (as Metal Gear Solid: VR Missions) and Europe (as Metal Gear Solid: Special Missions).
Late 2000 saw a PC port of Metal Gear Solid: Integral released in Europe and North America.