Career
He joined Square (now Square Enix) in 1987, where he has directed or produced every game released in the Mana series (as of 2006). He has also contributed to several games in Square Enix"s SaGa and Final Fantasy series, and created the well-known chocobo and moogle characters. Square Company/Square Enix
Koichi Ishii directed Final Fantasy I, II, and III, as well as SaGa Frontier.
He was invited to work on the original Final Fantasy in 1986, and helped develop the crystal theme that became a recurring motif of the series.
Ishii became the head of Square Enix"s Product Development Division-8. Mana series
He wanted to create a game called "Seiken Densetsu" in 1987, but Square rejected the idea before he even finished planning lieutenant
He was able to develop it in the early 1990s as a Final Fantasy Gaiden. He was involved in the development of the Sword of Mana and all other World of Mana games.
The World of Mana series was conceived to be a way for players to experience the Mana (series) in many formats and gameplay styles.
On Heroes of Mana, development of an Real-time strategy game became so difficulty they had to start development all over at one point. Another challenge of game development was due to the Japanese gaming audiences lack of familiarity with an RTS style of gaming. The world of Seiken Densetsu 3 was chosen due to its plot involving warring states, which was thought to be well suited for an RTS game.
He left Square Enix after the release of the World of Mana series.
Grezzo
He formed the new developer Grezzo in April 2007. Koichi developed the game Lincolnshire Attack Heroes for Wii.
IGN called Ishii one of the top 100 best game creators ever. Ishii is noted for his use of an active real time battle system, a pioneering move at the time.
Some critics felt that the constant switching between a battle screen and the world map made the games feel faster paced and "deeper".
He was also praised for his use of cutting edge technologies such as Mode 7 graphics to create a 3D feel.