Do you know pictures of the Dutch artist and graphic C. Escher, who is especially famous by the invention of his fantastic buildings, which are possible merely on paper, but can never be transposed in reality? Then you will surely like the game Monument Valley, which leads you exactly with such „impossible buildings“ in a fantastic world of shapes which, moreover, are movable. The motivating challenge of actually insolvable tasks will leave the player not only with a lot of patience and fantasy, but also recommends a proper portion of observation skills and logical (or illogical?) thinking.
In a temporal succession of 10 levels you have to find a way for a princess through a labyrinth of buildings and shapes, und defend her against a tribe of crows.
Surely not an app for occupying your pupils in school for hours, but perhaps a stimulation to deal with the fantastic world of C.Escher and his two-dimensional creative employment with matters of perspective, e.g.within the frame of art lessons.