Yosumin! is kind of different in how it works. As you’ll see on the first stage, different panels are scattered around a huge grid and you need to find four that make up the corners of a rectangle. This can be four together in a square or four that take up the entire board (clearing the board in such a way is called a Yosumin!, kind of like Yahtzee). The only requirement is that your rectangle’s four corners are all the same design. You clear a rectangle by clicking its opposite corners (like upper right, lower left). Your goal is to group in as many panels as you can within your rectangle to meet the goals listed on the left before time runs out.
As you progress, goals get more complicated and time runs faster. Occasionally, gold panels will show up. They can be used as corner pieces and, when you clear them, they add significantly more time to your counter. Giant panels will sometimes appear as well, and they can be cleared the same as gold panels: either within a rectangle or as one of its four corners.
If you like this addictive little game, you can import a full retail game from Japan, or simply download the Steam version for less than $5. The full game has more varied gameplay, a click-drag feature for creating rectangles, and many more goals and tweaks throughout. It’s a full package and if you liked playing this, I highly recommend you buy the full game. You won’t be disappointed.