Earth-Moon is a game. You are shown two images, one of the Earth and one of the Moon, and the relative size of the images accurately reflects the relative size of the Earth compared to the Moon. The aim of the game is to position the Moon so that its distance from the Earth is accurate relative to the size of the two bodies.

The idea is to improve people's intuitive understanding of how far away the Moon is.

This would make a great game if done with physical models. E.g. at a school fair.