Developer Level 5 has revealed there is a 100-hour unlockable RPG game within DS title Professor Layton and the Devil's Flute.
The bonus feature is called Professor Layton and London Life and will be made by Brownie-Brown, a Nintendo-owned Japanese studio responsible for DS titles Mother 3, Magical Starsign and Blue Dragon Plus. The founders of the studio cut their teeth on the Mana series many moons ago.
Joystiq has screenshots of London Life, which appears similar in style to Professor Layton - cartoony characters wandering around in top hats. The RPG was apparently originally meant for mobile phones.
Professor Layton and the Devil's Flute will be released on 26th November in Japan. There is no European date.
Indeed, Europe still awaits the release of Professor Layton and Pandora's Box (Diabolical Box elsewhere). That adventure-puzzle should be with us on 25th September, and previous instalment Professor Layton and the Curious Village suggests it will be well worth the wait.