Warhammer 40,000: Space Marine 2 is out. That’s technically true, in that you can play the action game right now. The official release isn’t until September 9, but like many of today’s biggest games, paying more upfront unlocks the game a few days early for you.
In this case, purchasing the gold or ultra editions of Space Marine 2 is what lets you play early, and thousands of players have done so.