perfectly.violet1.0a simple yet elegant design
Round Up's rules are simple. Move a marble to the blank space by clicking it or by using the cursor control keys. You can only move a marble that is next to the space. You can move up, down, left, or right, but not diagonally. You can only move a marble when: a) it is next to a marble of the same color before the move, or b) it will be next to a marble of the same color after the move.
The goal of the game is to move all of the colored marbles to their colored backgrounds.