Microsoft has clarified the terms of its free Limbo promotion, confirming that those "who played their Xbox One the first weekend of launch" were selected to receive "early, free access to the game".

In a statement provided to VideoGamer.com this morning, a Microsoft spokesperson said:

"We're looking forward to launching 'Limbo' on Xbox One. As a thank you to our earliest adopters, fans who played their Xbox One the first weekend of launch received early, free access to the game. 'Limbo' will also be available for purchase via the Xbox Game Store soon."

Clarification follows messages sent to some Xbox One users this weekend granting them access to a free copy of Limbo. However, there still appears to be some confusion over who was eligible after some early adopters failed to receive the message.

"The Year One Celebration gift box email was sent to Xbox One customers who purchased the console between 11/22/13 - 11/11/14, in our 13 launch markets, are 17 years or older and have 10+ hours of usage on Xbox One," the spokesperson continued, referring to Xbox One's free birthday goodies. "Gifts were distributed entirely at random to Xbox One owners from all 13 markets who opened their email and clicked through to the web page."

Microsoft has yet to announce when Limbo will be available to purchase separately on Xbox One or for how much. Rumours point to a release early next week.