There are injustice in this world. Innocent animals and birds are put to death. Poor and weak people are tortured. Is God happy with this world?
Our Scriptures and saints say that God created this world out of His Own Self just to enjoy infinite types and proportions of pains and pleasure.He was not satisfied while being alone. He Himself started playing in form of many :एकोऽहं वहु स्याम् meaning from One I shall become many.
We do not understand our real nature and so suffer.The spiritual practices are for getting the grace of God or the Self and get liberated from all these pleasures and pains. (Reference:Sri Ramakrishnakathamrita)