You can see Olive Oyl singing He's Large here:
Here's the scene where they find Swee'Pea:
Roger Ebert calls it "lots of fun". Slant Magazine has a positive review. DVDTalk has a mixed review, calling it "certainly too good-natured a film to actually hate". The New York Times says it
is a thoroughly charming, immensely appealing mess of a movie, often high-spirited and witty, occasionally pretentious and flat, sometimes robustly funny and frequently unintelligible. It is, in short, a very mixed bag.
I must join the chorus of those praising Robert Altman’s Popeye. Popeye is a film that is at times difficult, but eventually holds persistent charm.