Microsoft entering the console market in 2001 with the original Xbox was met with skepticism. Why would a Windows company succeed where others had failed? The answer was Halo: Combat Evolved. Bungie's sci-fi shooter proved that first-person shooters could work on console with twin-stick controls, and its campaign plus four-player split-screen became the killer app that moved hardware. The Xbox also introduced a built-in hard drive and ethernet port, laying groundwork for Xbox Live. Microsoft lost billions on the original Xbox but established a foothold that grew into a gaming empire.