Jonah is really angry at God for saving the people of Ninevah. The climax, point of the whole story is not the fish, but the relentless, irresistible, restoring Grace of our Heavenly Father. Jonah is displeased enough with the situation to die...just die. He is angry with God because he knew God's character enough to know that God would in fact forgive the Ninevites and Jonah thought they were beyond forgiveness...much like the brother of the prodigal son. We find ourselves identifying with Jonah and the brother but we need to NEVER FORGET the grace that we have been shown. The same grace God showed the Ninevites, he shows to us and all who believe.