An ex-member of STI, Craig Sitt has found screenshots of a cancelled Sonic game proposal. It was to be a spin-off featuring Tails, named Treasure Tails. The game seems to be an isometric puzzle platformer taking place in a South American-like temple. The stills weren't created by Craig, rather Bill Dunn, who pitched the concept in February 1993. Please note that these are only concept images for a pitch, there most likely isn't any sort of prototype.