A variation on the normal musical chairs, which adds a ‘collision’ element to it.
Arrange the chairs so they are facing outward in two circles that are within 6 or so feet of one another. Play as in normal musical chairs, but players walk around the circles in a figure-of-eight pattern, i.e. clockwise around one circle then anti-clockwise around the other circle. The crossing over between the circles adds a collision element. Because of the strong potential for collisions, be aware if you are thinking of playing this with young children who could perhaps be easily hurt.