This sounds like a really great idea. But it would be just general stuff and will not capture the gaming experience. In Mass Effect 2 for example, my most memorable moments were not the story twists. It was several fights where I was outnumbered and outgunned. Standstill shootings in alleys lasting several minutes, where I hop from cover to cover trying to gain position or land a special power hit. That's what gaming is for me and it can't be quantified by a spreadsheet of statistics.