Teebo & Kai

Teebo & Kai is an unannounced cooperative platform game commissioned by Valve that was being developed by Escape Factory from 2000 to 2001. Harnessing Valve's GoldSrc engine, the game would have seen two players work together across various alien environments.

The project began development on August 14, 2000 when the Escape Factory team moved into Valve's offices. Although feedback from playtesters was encouraging, the game was ultimately canceled on April 25, 2001 when Gabe Newell decided that it would be a better idea to port Team Fortress Classic to the Xbox instead, though that port never saw the light of day either.