A fun game for the younger ones.
These are big wooden blocks, that allow you to match the inner geomoetrical form, but it can be used in so much more ways.
You could use the outer form as a place to sort things. You could ask 2 year olds to bring you things they see around the house of a certain color. Or sort same category things (cars, animals, etc)
But you can also use them creatively to create a "picture". Bring some natural materials from outdoor and create your own game/picture.
The limit is just your imagination.