NStepBack tests how good your memory can be for objects. Four shapes, i.e., spade, heart, diamond, and club, each with four different colors, form a total of 16 objects. In this game, objects appear sequentially and the goal is to compare the current object with a previous one that is 1-step, 2-step, 3-step, 4-step, or 5-step back. Players have to tell whether or not the colors and shapes of the two comparing objects are identical. There are four possible cases: 1) both the colors and shapes are identical, 2) only colors are identical, 3) only shapes are identical, and 4) both colors and shapes are different. To obtain a point, players have to click on both the C (color) button and the S (shape) button for case 1), the C button for case 2), the S button for case 3), or do nothing for case 4). Try it now!