This game plays a significant role in the 2007 Mike Bender film Reign Over Me. In the film, Charlie Fineman plays the game to cope with the death of his family in the 9/11 attacks, as the imagery of each Colossus falling to the ground was considered reminiscent to the collapse of the World Trade Center. With the approval of Fumito Ueda, the game was included in the movie.

It is not said in the game, but Team Ico has stated that the main character's name is Wander and the woman that he attempts to resurrect is named Mono.

If Wander walks up to the side of Agro, and the player presses the circle button, Wander will gently pat his horse.

Almost every Colossus has a view of the Shrine of Worship.

The game was originally intended to be a sequel to Fumito Ueda's previous game, Ico (2001); early in development, it was known under the title "Nico" ("ni", Japanese for "two", plus "Ico").

The game contains sixteen boss fights that the player must win in order to complete the game.

If the player eats enough lizard tails and maxes out Wander's stamina, they will be able to reach the secret garden up high in the shrine of worship. The garden is very difficult to reach, but if the player climbs up the front of the temple and makes it to the top of the bridge, the garden can be found. This is in fact, the same garden that Mono and Agro take the infant up to at the end of the game.