Turbo

Based on the 1981 Sega coin-op of the same name, Turbo is one of those prototypes that everyone was sure existed somewhere (it was shown at the 1983 CES once), but never seemed to show up. Thankfully all this changed when former Atari 2600 programmer Anthony Henderson happened to stumble across his long lost copy of Turbo while searching his attic. According the programmer, Coleco originally wanted the game to use paddle controllers in order to better simulate a steering wheel. However reading the input from paddle controllers takes up considerably more clock cycles than reading regular joysticks, and there was not enough time to animate the road edges. After pleading with Coleco, they were allowed switch the game from using paddles to joysticks, which freed up enough time to insert the road edge movement but the game was cancelled before it was actually implemented. Other missing features include the ambulance, water puddles, and the enemy car AI (although implemented in the current prototype, it was never tweaked and finalized). The game difficulty also needed to be tweaked a little as dodging oncoming cars in this version is more a matter of luck than skill. According to the programmer there was actually one more revision of the game completed before the project was cancelled that included moving trees on the sides of the road on the curve stages. It is unknown what happened to that particular prototype.