It was quite odd to see Halo Wars 2 announced at Gamescom last year, but it was also pleasantly surprising.
I wasn't sure we'd see it until that show again, but Microsoft have indeed brought it to E3, as was leaked out yesterday. They've shown off this trailer for the game and it looks pretty wild. It shows a cool cinematic, and it is really quite lovely. A nice track, a huge scale battle. A real call back to the best Halo trailers.
And here is some gameplay:
That game is out February 21st, 2017, but there is a beta out right now. So get on that!