Games like Assassin's Creed Odyssey played on a giant background screen as Google CEO Sundar Pichai and other company executives unveiled their latest product in March. Stadia, a new game-streaming platform, will allow people to smoothly stream blockbuster games to smartphones, tablets, PCs and other devices running Google's Chrome browser or YouTube. Pichai promised a "new games experience." But his was only the latest shot fired in a battle royal that's brewing over the future of gaming.