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Microsoft E3 surprise: Halo Wars 2 Open Beta will take place from June 13 to 20

Probably Microsoft was waiting for the E3 Media Briefing for the announcement, but someone must have turned on the switch early on the Games Store: as you can see from the two screenshots below, Halo Wars 2 Open Beta appeared in the store - though not accessible via direct search - and according to the pages it will take place from June 13 to 20, with a download size of 13 GB.

So it seems that Microsoft is preparing to let us try Creative Assembly's game during E3: get prepared if you're an Halo or RTS games fan!