Reflexion about the term playful

Why play or playful? And what is playful?: I have to find a reason, probably because is one of the most innate and innocent faculties in the human being.
It is not just about playful things, that is why those that are catalogued as objects that embody the characteristics of play, there are objects, substances and materials that normally we don’t identify as playful but potentially they are.
Things can become playful if they are used in a specific context and performing something specific.
Water is not a playful element itself, it can be used for different things, to drink, to get a shower, to clean our clothes, but if we design a thematic park were water is the main element we are creating an environment were the water is the main character and people is interacting with it, water has become playful. Same when it is used to fill balloons and start water war in summer.
I have seen some other examples when water become playful as for example the waves in the sea to do surf, or the fountain in Russell Square that interact with the people that approach to it.
A cube is not a playful object, it is basically a shape that can be used for different matters, for a box, for a house, etc…. but if I give him internal mechanism and movement it turns to an object which with I can interact, and therefore it becomes a playful object.
Same happens with other objects as for example a rope, it has several uses as we know it can kill, but if I hang it from the ceiling I can use it to climb through or as a liana to swing.
It can be playful just the use of the color.