Klax is an action/puzzle game, the object is to catch assorted color falling tiles and create rows, columns, or diagonals of a single color. Each level requires a different pattern to be made, and the tiles fall faster, more at a time, and in an increasing number of colors as the game progresses.

In Klax your primary job is to line up three or more tiles of the same color in rows, diagonals or columns, effectively scoring a Klax. A Klax removes the aligned tiles from the screen.

Set against varying outer space backgrounds, Klax has you controlling a paddle that moves horizontally across five slots positioned in front of a vertical conveyor belt. The tiles descend toward you from this conveyor belt, and you should catch the tiles to put them in a bin which is located below your paddle. The paddle can hold up to five tiles at once. You can throw a tile back on the conveyor belt if you don't want to put it in your bin just yet.

There are five different types of waves in this game. Each one requires you to perform a specific task before you move on to the next stage. The tasks include catching a certain number of tiles, scoring a certain number of points, and getting a certain number of Klaxes, whether all diagonal, all horizontal, or any combination of the three kinds of Klaxes.

If you let a tile get by without catching it first, it will increase your drop meter. Let this happen too many times and your game is over. Also, the game will end if the tile bin gets full before you can finish a wave.