Warhammer 40,000: Gladius - Relics of War, besides being far too segmented of a name, is an upcoming 4X turn-based strategy set in the Warhammer 40k universe that will have you lead one of four factions: Space Marines, the Imperial Guard, Orks and Necrons. As you might expect given the differences between them, each one will feature their own unique units, buildings, technologies, and most importantly of all, playstyle.
Besides their gameplay differences, each faction will also have their own individual storyline to explore as you venture across Gladius Prime, a world heavily tainted by the warp. No story details have been revealed just yet, but you can expect to see randomly generated maps filled with powerful ancient artifacts, hostile wildlife, and various resources you'll want to secure before your enemies get a chance to do so.
Along your path to wold domination you will need to construct cities, fill them out with buildings and fortifications, and then create vast armies with which you can push back the other factions. Additionally, you'll be able to recruit powerful Hero units that posses equally powerful abilities that can help you turn the tide of war in a pinch. And if that isn't enough, you'll also have a chance to upgrade them with items and artifacts you uncover throughout your journey, thus in true Warhammer 40k fashion making your Heroes nigh-unstoppable killing machines!
You can get a bit of a sneak peek of what Gladius - Relics of War looks like in-game through the somewhat recent announcement trailer. It's not very long or very detailed, but it'll at least give you some context to my ramblings. Have a look:
If you would like to give Gladius - Relics of War a try for yourself and see if it's the type of game you'd enjoy, you should head on over to the official website in order to sign up for the closed beta. The whole thing is under NDA so I'm not sure if the beta is currently ongoing or if it's planned for the future, but if you're curious I suppose it's worth signing up regardless.
As for the release date, Gladius - Relics of War is set to arrive in "early 2018", though no actual date has been given just yet. If you would like to learn a little bit more, with the emphasis here being on "little", you should head on over to Steam.
And finally, here's a couple of screenshots, just to send you on your merry way. Don't forget to click on them for the bigger version!