What could it be? according to an unconfirmed source, they have identified the ‘First Strike’ listing as a secret internal beta for the upcoming game. But the thing is , if it is internal only, then why did it shown up on the Xbox Live marketplace (it used to show up, now it is removed)?
‘First Strike’ seems to be the version released to game reviewers, featuring a couple of single player levels, or some multiplayer maps. The listing has already been removed from the website, but you can see what it looked like thanks to the screenshots below.
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it features some screenshots taken from the trailer,
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Another interesting thing: there is also a ‘download to Xbox 360′ menu and also mentions of prepaid codes. This will ring a few bells since this is exactly the same way which Halo Reach was leaked.