Kreton (Jerry Lewis) is not from Planet Earth, he hails from somewhere across the galaxy where he is a student at an alien university, though often he drives his tutor Mr Delton up the wall with his goofy antics. Such as taking a flying saucer and piloting towards the Earth, which he is engrossed by, with a view to meeting some famous military men of the American Civil War, in full costume so he will fit in though being an alien he still has powers undreamt of by human terms. However, one of those powers is not good navigation, and he winds up in the United States of 1960 where the inhabitants of the mansion he lands by are convinced he is there for a fancy dress party...
When Gore Vidal wrote his play Visit to a Small Planet, it was a state of the nation tract in science fiction format, a scathing satire on where the land of his birth was going wrong as far as he saw it. This was broadcast on television in the mid-fifties before transferring to a highly successful run on Broadway where Cyril Ritchard won plaudits for the central role of Kreton, so obviously Hollywood wanted in on the action and Paramount secured the rights. However, to Vidal's dismay, his finely honed barbs were thrown out of the window in favour of retooling the material as a vehicle for megastar comedian Jerry Lewis, about as far from urbane and biting observations as you could get.
Lewis was known for his physical comedy and verbal absurdity rather than any great wit, in his familiar screen persona anyway, hero to a generation of children who had little to no interest in tackling the political situation of the day, so the studio were not about to have him change his act now, nor did he feel comfortable in straying too far from his formula (though he often garnered encouraging notices when he did). His work in this film was not as downright weird as what he did with another singular talent when Kurt Vonnegut was on his radar in Slapstick of Another Kind, but if you were seasoned in the aggressively critical work of Vidal, you would wonder what they were thinking.
This could be any kid-friendly science fiction comedy really, and the source material was so far from what they ended up with in the movie that it was a mystery what they thought they were improving by adapting it this way, other than blanding out the opprobrium in favour of the usual Lewis mugging and physical hijinks. Here Kreton (a name that makes you link to the word "cretin" in this context, though Lewis is not a complete idiot here) falls in with a political commentator (Fred Clark), whose daughter (Joan Blackman) is considering whether to attend college, get married (to Earl Holliman in his usual amiable lunk role), or do both, and in what order. Kreton somewhat out of the blue is quite taken with the woman, and a love triangle is created, with the spaceman impressing her with his tricks.
Said tricks suited Lewis in that he could use props and effects to comic effect, he was often content to implement a fantastical edge to his humour though this was more usually down to the world his characters existing in being pretty crazy to begin with, no matter how many middle-aged men he was able to exasperate with his behaviour. So there was an invisible barrier between Kreton and everyone else (though he could touch others if he wanted), anyone who tried to tell someone else that they had just met an alien would find themselves reciting "Mary Had a Little Lamb", he could float, he could broadcast others' thoughts, and so forth. To mix things up a tad, Mr Delton started to play havoc with his pupil to teach him a lesson that Earthlings were not worth hanging around with, not because of wars or anything like that, more out of an authoritarian sadism which rendered the previously lighthearted tone offputting in the last act. There were scattered laughs, but this was nobody's best work. Music by Leigh Harline - and drummer Buddy Rich in the beatnik sequence.