Microsoft has sent out emails to some Xbox One fans for showing "dedication" and rewarding them with a free full version of launch title Killer Instinct according to NeoGAF users.
The email reads:
"Thank you for your dedication to Xbox. We want to show you our appreciation, so we're giving you: Killer Instinct.
"We've unlocked all characters so you can hit the ground running. Watch your inbox on November 22nd for instructions on how to claim your free gift. Don't worry, we'll remind you."
Killer Instinct has a basic version which will be available to everyone for free but comes with only a few of the characters included in the full roster – the rest must be bought. You can find out more about the game's pricing model here.
The game is being developed by Double Helix rather than series creators Rare and was announced at E3. Some Xbox One Day One Edition purchasers will also be getting other free titles including FIFA 14.