Siliconera, who picked up the rating, note that the name suggests this could be some kind of PlayStation Move spin-off title. Seeing as Supermassive Games (the studio behind Tumble and Start The Party) are listed as the game's developer, it's very likely.
Other suggestions around the 'net hint that this could be a bonus-disc included with LittleBigPlanet 2. Media Molecule have promised to include a sneak-peak at the PlayStation Move integration within the full-blown LBP sequel. Personally we're hoping that this is something completely new — a short adventure utilising the PlayStation Move and incorporating LittleBigPlanet's whimsical style. Could be amazing, and it would be brilliant to see Sackboy is a new gameplay style.
We'll have to wait and see. We're very excited to hear more though.