Try to fill in the whole grey area with the blocks from the conveyor belt. Click to move them, and press space or your left mouse button to rotate the pieces. Unused pieces will fall in the trash, but will lower your score. You can get bonuses for making large groups of matching color. Create a pattern using many differently shaped pieces by choosing a shape, rotating it to fit, and placing it on the template. The pieces drop into the trash if you do not use them in time, and will cost points.