GameZone says, "Spirits for iPad is like a modern day Lemmings, but with the grace, style and cerebral music of modern independent titles like LIMBO and Braid. It’s beautiful relaxing, deceptively simple, and sometimes, unfortunately, a bit boring.
In Cardboard Castle, you are a Knight in a world made of cardboard as you roam the stiffened paper land in search of the opportunity to do the sort of tasks that knights tend to do. Save princess, defeat monsters, and of course, turn cardboard into wet clumps of paper mache. These are all commonly referenced Knight activities."