(For a much better tutorial, play the actual Kongregate game - linked in Notes and Credits.) Move the player with your mouse. When you're close to someone, you gain happiness from their company. The closer you get, the happier you are. Too close, however, and you're killed by your reliance. When you're close to 2 people at once, you gain twice as much happiness as what you'd normally gain from both of them combined. With 3 people, you gain thrice as much. Gain as much happiness as possible before you die.
Based on https://www.kongregate.com/games/Contrebasse_/love Not a completely accurate reproduction, though - I took a liberty here and there.