You will have an easy, medium and hard trial to complete, in the first you have to resist two minutes, in the second a little more than 3 minutes and in the last, five minutes.
When they start to get sad a little red bar will appear next to their heads, showing the level of discomfort, so in order to make them happy again, you will have to give them what they want.
To do that you will have to pick one thing from the list, give it to the little ones, use the Left Mouse button and move it in the right direction.