Instructions are on screen. When you do something to your Babee, click on the corresponding button. Babee will cry until you do the correct thing. The timer on top is how long until Babee cries, which you can toggle with either space (This disables the toggle button), or the toggle button. Sometimes it'll reset. Don't worry. It's supposed to do that. It's realistic, so it might take a little while until Babee cries. In the meantime, play with him.
Hopefully that's a valid link. Sound Effect from https://pixabay.com/sound-effects/?utm_source=link-attribution&utm_medium=referral&utm_campaign=music&utm_content=64996 Elsewise, it's the first result of: https://pixabay.com/sound-effects/search/baby-crying/