Klax for Game Boy Color is a port of the 1989 coin-op game by Atari Games. As in the arcade original, players must stack a series of colored tiles into one of five bins as the tiles tumble toward the screen on a conveyor belt. This handheld version features all 100 levels found in the arcade, each of which can be accessed via password, as well as the original's digitized voice and sound effects. Players can also jump to a series of waves by selecting one, six, or 11 from the menu screen. Other options include three difficulty levels and a freestyle mode to practice making matches or Klaxes.