Microsoft has released a demo for Halo Wars 2, so if you've got a PC with Windows 10 and want to check out Creative Assembly's RTS take on the Halo games you should head over to the Windows Store.
The demo has the first mission of the campaign and access to the Blitz Firefight mode. Halo Wars 2's big new feature is the Blitz modes, that see base-building replaced with a deck of cards that you can play to summon units to the field. I tried out a blitz mode at a preview event for Halo Wars 2 and thought it was a really great new approach to RTS games. The version I played was a versus multiplayer game, whereas firefight sees you fighting back waves of incoming AI controlled troops but you'll get a similar introduction to the unique system.