From the PlanetXbox360.com feature article:
"Video game developers are always trying to come up with the new gameplay mechanic that will take the industry by storm, something that not only adds to the fun-factor but can be implemented in a way that it becomes revolutionary. Now just because developers are trying to accomplish this feat doesn't mean it always works; today we have a list of the top five video game features that never caught on. Some were just too good to be true, others were dead before they made it out of the test labs. Games that included the below features may have been successful at retail, it's just unfortunate that the features didn't catch on with other franchises. Even though they are on this list we are still happy that developers are out there trying new things, and making attempts to create quality (and original) gaming entertainment for the masses, it's better than just pushing out a new title each year with a bigger number on it."