According to data from research firm NPD Group, the video game industry saw retail sales slide by 24 percent to $848.3 million, compared to the same month a year ago. Hardware sales suffered a huge drop in September, down 39 percent from a year ago to $210.9 million. Meanwhile, video game software sales dropped 18 percent. Software sales were down only 14 percent when PC game sales were factored into the number. Accessories were also down 11 percent.