Each puzzle begins with a monochrome grid of numbers, plus a few colored cells marked with an X. Starting at these cells, you must link up numbers in non-decreasing order until the whole grid is filled with color. Cardinal Chains is a simple and minimalist game but will challenge your thinking skills. In order for you to proceed to the next level, you need to line up the number in a non-decreasing order. A minimalist puzzle game centering on the concept of non-decreasing sequences.