In the early '90s, Nintendo dominated the video game industry, holding over 90% of the market. It would be foolish to challenge that dominance, but that’s exactly what Sega did. With an aggressive marketing campaign and a new star in Sonic the Hedgehog, Sega solidified itself as a top contender in the industry and a force to be reckoned with. However, its reign at the top was short-lived, as it eventually caused its own downfall with a series of tragic mistakes. Here’s how Sega rose to the top and then plummeted to the bottom.