To insert the 3D objects into the box, simply tap. The same objects will be gathered in threes. You succeed once you've collected every object. You fail if there are 7 items on the boxes! Be careful when using the timer; you should tap quickly to match objects. After finishing a level, you'll discover new items to pair. The game has a good amount of difficult, well-designed levels that will exercise your memory and train your brain. It is the best way for you to kill time!