The Master Chief’s iconic journey includes six games, built for PC and collected in a single integrated experience. Whether you’re a long-time fan or meeting Spartan 117 for the first time, The Master Chief Collection is the definitive Halo gaming experience.
Do note that Microsoft wants you to make a Microsoft account on top of your Steam account before you can play.
Do you need a Microsoft account to play single player, or just multiplayer?
Required for single player as well.