Play the game until you get to the stage where you are supposed to find cats by turning the light on and off. Instead of playing it normally, you need to keep on flicking the light switch on and off quickly by pressing the up and down buttons on the D-Pad. Keep it up for about a minute. The trophy will pop up when you've done enough. You might need to try a couple of times to get a good rhythm. You definitely won't get a good score in the game, but the trophy will be yours.