I wouldn’t say that a written script is improvisation, though I have known jazz musicians to plan out the “improvised” solos they intend to play. However, I think “improvising around the fairy tale” is a good way to describe what I expect to see here.
A movie centered around a big green thing and a golden thing (unless the only treasure in this version is the woman) seems like a good choice for an early commercial color film.
What can one expect from an Abbott and Costello movie? Bumbling into trouble, one-liners, slapstick. I can’t point to anything about this movie that I think is going to be truly remarkable. It’s a vehicle picture coming out of the Hollywood machine of the Golden Age contract films model.
I have nothing to point to that I’m very interested in, beyond seeing Abbott and Costello get into trouble and be silly for a bit. They’re what sell the movie, which is the whole point.