A mobile phone version of Metal Gear was released only in Japan on August 18, 2004. The game is based on the original MSX2 version, but includes several additional features and changes. This version is the basis of the subsequent re-releases. New Easy mode - The player can choose to play with the original MSX2 version's difficulty or with an easier difficulty setting. Boss Survival mode - After clearing the game once (regardless of the difficulty setting), a new game mode is unlocked, in which the player can fight against all of the main game's bosses. The player will be awarded with a title based on their clear time (this is also the case in the main game). Infinite Bandana - A hidden item that becomes available to the player after clearing the game once on either difficulty setting. Like the bandana featured in Metal Gear Solid and Metal Gear Solid 2, this will conserve the player's ammunition to the present amount while firing. Rewritten script - The Japanese script has been rewritten to include hiragana and kanji, in addition to romaji and katakana. Name changes - Several of the game's characters had their names changed in the mobile phone version. Removal of passwords - The passwords that are featured in the MSX2 version have been removed.