I/O (video game)

I/O is a Japanese science fiction visual novel produced by Regista. It was released by GN Software for the PlayStation 2 on January 26, 2006 and by Asgard for Microsoft Windows on August 29, 2008 under the title I/O Revision II.

Gameplay
I/O is a mystery adventure visual novel in which the player takes the role of one of four characters; depending on who they choose in the beginning of the game, they experience different scenarios. At certain points throughout the game, the player needs to select one of two choices in order to move the plot forward. In order to reveal the truth behind the game's story, the player needs to clear all four routes.

Setting and characters
The game is set in Tokyo in 2032, and follows four protagonists: Hinata Aoi (葵 日向), a lethargic high school student who is investigating the disappearance of his twin sister Mutsuki (夢月); Ishtar (イシュタル), a woman who is the leader of the hacking group Criminal; a second Ishtar, who is searching for something important; and a man who goes by the nickname "{HE}", who does not have any friends, and who is opposing an organization.

Among other characters are the Criminal members Mika Ayase (綾瀬 みか), Kousuke Miyata (宮田 浩介), and twin sisters Mayumi (真佑実) and Masami Shinozuka (篠塚 真佐実). The player also encounters Hinata's childhood friend Sakuya Kawahara (川原 朔夜).

Development
I/O was developed by Regista, and was directed and written by Takumi Nakazawa, based on an original concept by Nakazawa and Romeo Tanaka, and features character designs by Soyosoyo. The game was inspired by a Mesopotamian poem, the Epic of Gilgamesh. It features full voice acting for all characters, including the protagonists.

The game was announced in March 2005, and originally had a planned release window of the third or fourth quarter of 2005; it was showcased at Sega's booth at Tokyo Game Show 2005 in September, and was eventually released by GN Software for PlayStation 2 on January 26, 2006, in both a standard and a limited edition. A Microsoft Windows version, titled I/O Revision II, was released by Asgard on August 29, 2008. The game's soundtrack album, I/O Perfect Audiotracks, and the drama CD I/O Overbrowse Damsel, were both released by Five Records on February 24, 2006.

Reception
Writers for the Japanese video game magazine Famitsu appreciated how new developments occur after clearing each of the game's scenarios, and found that the game's worldview was consistent despite referencing various conflicting texts, such as the Bible and the Epic of Gilgamesh. They also felt that the game's use of themes such as virtual and real, human life and ontology gave the game a "cyber-science fiction youth" feeling.