Polarium

is a 2004 puzzle video game developed by Mitchell Corporation and published by Nintendo for the Nintendo DS. It was a launch title in Japan, Europe and China. In the game, players use a stylus to draw lines on the DS's touch screen, flipping black and white tiles to clear puzzles.

==Gameplay== The player selects tiles by drawing lines over them with the stylus. Selected tiles will flip from black to white or vice versa. In the standard Tetris-like challenge mode, players must make room for falling tiles by clearing rows as they pile up on the bottom screen. Rows are cleared by flipping the tiles to make rows that are all black or all white. Surrounding the main puzzle area are gray "neutral" tiles that have no effect on the puzzle but can be used to flip disconnected groups of tiles in a single pass. The scoring in Challenge and Versus mode are based on how the lines are cleared; for example, more points are given when more lines are cleared (lines), when numerous lines are cleared with just one stroke continuously (chains), when there are 2 separate lines cleared with uncleared lines between them (split), or when several lines are cleared in one stroke, but different lines have different polarities (borders).