Numblast

Players control a 2x2 cursor which is used to rotate groups of four cubes either clockwise or counter-clockwise. When four or more of the same cube form a square, they turn red and rotate, and their number increases by one (four cycles back to one). If another square is then formed, the relevant cubes also turn red and rotate. This process continues until no new square is formed, at which point all the red cubes disappear and points are awarded (a "Numblast" occurs when the entire play area is cleared in the same combo). A few seconds later the empty spaces are filled with random cubes. If the player fails to clear a cube within a certain time, it will turn black, and if all cubes turn black, the game is over. If four black cubes of any number form a 2x2 square, that square cannot be rotated (although the individual cubes within the square can be rotated if the player's cursor covers at least one non-black cube). After a certain number of cubes have been cleared, a special star cube appears which can occupy any number. When the special cube is used as part of a square, it eliminates all cubes of whichever number the square is otherwise made up of.