Penguin Project:Disney's The Little Mermaid Jr.

 In a magical kingdom fathoms below, the beautiful young mermaid Ariel longs to leave her ocean home to live in the world above. But first, she'll have to defy her father, King Triton, make a deal with the evil sea witch, Ursula, and convince Prince Eric that she's the girl with the enchanting voice.

This is has a run time of about 75 min with a 15 minute intermission