Risha this is a great idea! It gives a platform to people who want to display their work but are too shy. It gives how you said; a way... "to express your creative side without being afraid of how it will be judged". and for them to be anonymous would be cool, so they hear people say that their work is great and this would make the happy, and boost their creative confidence.
This is a great idea! I like the whole idea from the huge amount of creative freedom they have when building or drawing something from everyday materials. And It being a group activity with people in the local community, i especially like the fact that they would be improving their problem solving, and also developing their collaboration skills.