Oh my glob, it's an online Choose Your Own Adventure Time!
Once Upon An Ooo is an illustrated adventure that's part text-based – so similar to the Fighting Fantasy books we used to read/play as kids (except with mouse clicks replacing the 'turn to page 74 to be eaten by dragon) – and part point-&-click.
The story features familar characters, is child-friendly and kinda personalised (characters call you by whatever name you tell it you have).
The game was created by Maidstone-based We Love Digital for Cartoon Network. The agency says that they've tried to design a game that appeals to newcomers, fans and superfans.
You can play the game at ooo.cartoonnetwork.co.uk. Season 7 of Adventure Time starts showing this autumn.