What's Up With the Title?
This movie's a lot of things, but subtle isn't one of them. It wears everything on its sleeve: emotions, personality…everything but those space eels, which have another home.
Accordingly, the title basically sums up the whole story in a neat little phrase: Star Trek II (because it's the sequel) and The Wrath of Khan (because there's a guy named Khan who's awful wrath-y). Cue the theme music and tell Mr. Sulu to hit the gas: that title leaves us ready to go.