became a full 3D game with a view set on a floating plane. Kosaka completed design documents before the 32X was released, without a clear picture of the hardware. Some of Kosaka's concepts were new dynamics to the gameplay, including the ability for a second player to play as a character other than Tails. Various playable characters, including some from the cartoon, would be unlocked as they were rescued and have unique moves. Players could also collect Chaos Emeralds via special stages that involved playing a minigame similar to air hockey against Dr. Robotnik, and collecting all seven would unlock the true ending. In mid-1995, Kosaka resigned. According to Senn, "[Kosaka] and the executive producer Dean Lester were not getting along, and I believe Michael felt it was his best option to simply remove himself from what he thought was a politically unhealthy environment." Lester resigned later in 1995 and was replaced by Manny Granillo. Wallis, who had worked on The Ooze (1995) and Comix Zone, was placed in charge of Sonic X-treme. Lead programmer Don Goddard was replaced with Ofer Alon, who some staff found difficult to work with, saying he did not share his work. As the design had changed significantly and the 32X struggled commercially, development moved to a planned Sega cartridge console powered by nVidia 3D hardware, designed to compete with the Nintendo 64. STI technical director Robert Morgan was instructed to explore this possibility, without hardware specifications or development kits. This decision was made because of the planned console's ability to handle 3D graphics and Sega of America senior management's disinterest in the Sega Saturn. After Sega announced that it would focus solely on the Saturn, development shifted again, costing the team several weeks. When Naka visited STI and observed the X-treme development, he simply said "good luck". Design The Saturn version was developed by two teams with two different game engines, starting in the second half of 1995. One team, led by Morgan and including programmer Chris Coffin, developed the free-roaming boss levels. This engine used tools used by Saturn games such as Panzer Dragoon II Zwei and rendered bosses as fully polygonal characters. The other team, led by Senn and Alon, developed the main levels, working on PC with the intent of porting their work to Saturn. Alon and Senn focused on building an editor to construct the main levels. Music and backgrounds