Here is an overview of the game, via Polyarc:

Moss: Book II builds upon the story set forth in the platinum-selling Moss video game that ranks as one of the all-time top-rated virtual reality games to date. Having rescued her uncle Argus, Quill’s adventure continues with the revelation that a winged tyrant is hunting her within the hexed castle where her uncle was held captive. But Quill has a plan of her own, one that could finally end the merciless rule of the Arcane and save the world from a great unmaking. Lined with dangerous terrain, challenging puzzles, and enemies twisted in fire and steel, the journey will be trying—filled with triumph and heartbreak alike—but new allies, old friends, and the very nature of the castle itself can offer you help along the way.

Watch 12 minutes of new gameplay footage below, via PlayStation Blog.