From Wikipedia: Oni is a third-person action video game developed by Bungie West, a division of Bungie. Released in 2001, it was Bungie West's only game. It broke new ground by blending third-person shooting with hand-to-hand combat.

https://en.wikipedia.org/wiki/Oni_%28video_game%29

Confirmed working with OSX 10.6-10.8 up to 1920x1080x32 Intel-only

Instructions: Copy 'Oni f' folder from ONI.DMG to Applications

Overwrite the old Oni.app located in 'Oni f' folder with the one in the 'Oni1.1b5.dmg'

Details about the update can be found in the READ ME in Oni1.1b5.dmg.

Where to find more information about this free, community created(Bungie sanctioned) update to Oni: https://oni.bungie.org/community/forum/viewtopic.php?id=848&p=1