Katamino Duo – a.k.a., Katamini – is a junior version of Katamino, with two players competing on separate game boards (or possibly one game board divided into smaller spaces) to fill all of the empty spaces first. The game is played over a number of rounds, with each round becoming progressively harder.

Katamino Duo also works as a solitaire puzzle, with the solver trying to fit the pieces onto the playing area in different ways.