There are a few stories that follow this pattern... my favorite is the one about Starcraft development. While Blizzard was making nothing more than "Warcraft in space", a competing studio showed a beautiful and fluid RTS at trade shows that got everyone's attention. The Starcraft team had a hard time getting their product to the same level, and had to scrap a lot of code. It turned out that the other studio was just showing prerecorded videos at trade shows, while employees mimed the appropriate button presses to make it look interactive.