Nimbus is a sign of holiness and Nimbus, the cubic hero of the game, wants to get it. Apparently it's important to him. You can help him with this by passing the levels. On each of them, the halo will be in different places. While passing through the gray cubes, they will disappear, by clicking on the hero, you will make him move in the opposite direction. The level is passed if the hero reached the circle, and did not jump out of the playing field. Be nimble and the hero will get what he wants in Nimbus.