Clash of the Titans (1981)

Perseus is the favored son of the god Zeus, but he has unwittingly ticked off the sea goddess Thetis. Just to make things worse, Perseus falls in love with the lovely Princess Andromeda, who used to be engaged to Thetis’s son. Soon Perseus is off on one quest after another, with Zeus helping, Thetis hindering, and lots of innocent bystanders getting stabbed, drowned, and squished.