Explained in Gladstone's Games to Go, Cluster Buster is an abstract strategy game played with a cluster of objects (usually). Players remove objects from the clusters in an attempt to avoid removing the last object.

From Gladstone’s Games to Go:

Divide and conquer is clearly the key strategy for this game, but the more players you’ve got-and the more objects you play with-the more challenging you’ll find it. The setup of Cluster Buster can be as much fun as the play itself if you move beyond coins and use a colorful variety of playing pieces: You begin by creating a crazy mosaic, then erase it as the game goes on!