Storyboard images given to Develop indicate Lionhead built an adventure around its ambitious Milo project.
The site says it has verified that the concept pictures are genuine, and that they show a "secret forest" area that was in construction for the Kinect game.
Microsoft claimed late last year that Milo "was never really a product" and "was never announced as a game".
It's unclear whether Milo will ever make it to market or not, but Lionhead boss Peter Molyneux has spoken of the title as something consumers will eventually get to experience.
"What I showed in Milo was just a tech demo," he said last year. "I think everyone asked: 'That was pretty fascinating, but what does it all mean?' It's only when you see it in its entirety and play it that you realise it's robust enough for people to play on their own."