The cover used for the North American release of this game has been called one of the worst video game cover arts in contrast to the cover used in other regions, and considered a contribution to weak sales of the game in North America.
On the original Playstation 2 release, the American NTSC version of the game is missing several features that are present in the PAL versions of the game. These include: Co-op gameplay, a magical green sword, and if the player plays through the game a second time, Yorda's subtitles will be translated to english and a secret "Watermelon ending" can occur at the end of the game. Fumito Ueda states that this is because Team Ico "ran out of time" when porting the game to NTSC.
Although several features from the PAL version are missing from the NTSC version on the original Playstation 2 releases, the Ico & Shadow of the Colossus Collection HD for Playstation 3 is based on the original PAL versions of the game and has all of the missing features restored.
Fumito Ueda cites the games Another World, Lemmings, Flashback and Prince of Persia as the main influences for this game.
Fumito Ueda first came up with the concept of this game back in 1997.