in Bungie's earlier Marathon titles, tiers are color-coded, in this case by green (weakest), blue, and red (strongest). Also color-coded are the levels of health each opponent has, indicated by a flash when the player strikes or shoots them. Green flashes show the opponent has high health, red flashes show the enemy is near death. Oni does not confine the player to fighting small groups of enemies in small arenas; each area is fully open to explore. The fourteen levels are of various sizes, some large enough to comprise an entire building. Bungie hired two architects to design the buildings. The Oni engine implements a method of interpolation that tweens key frames, smoothing out the animation of complex martial-arts moves. However, frame slippage is a common problem when multiple non-player characters near the player are attacking. Development The game's universe is heavily influenced by Mamoru Oshii's anime film Ghost in the Shell, with some additional influence from Akira and the works of Kenichi Sonoda. The original plan was for Konoko to be a cyborg like Ghost in the Shells Motoko Kusanagi. The explanation for her superhuman abilities was changed to be more organic with the addition of the Daodan Chrysalis concept by design lead Hardy LeBel. Oni was originally expected to be released in the fourth quarter of 1999. Advertising was targeted towards that shipping date, and the game won E3's Game Critics Awards for Best Action/Adventure Game in 1999. However, development difficulties caused the release date to be pushed back continuously. The acquisition of Bungie by Microsoft in 2000 then led to the transfer of the Oni IP to Take-Two Interactive (which owned 20% of the studio prior to Microsoft's acquisition). Since Bungie's employees were moving to the new office location in Microsoft's headquarters or leaving the company, work on Oni had to be completed as quickly as possible. Due to a lack of time to resolve issues with the multiplayer code and to finish the levels intended for use by multiplayer mode, this functionality was omitted from the released version. A sequel was in development at Angel Studios for two years before being cancelled for unknown reasons. Music Half of the music was composed by Martin O'Donnell in collaboration with Michael Salvatori. Other tracks in the game, which had already been implemented before O'Donnell and Salvatori joined the project, were composed by the music company Power of Seven,