Cardboard Science: Gill-Man or Astro-Man?

THE CREATURE WALKS AMONG US

Loopy and unjustified, but at least there's some noticeable heart in the third and final chapter of the Black Lagoon trilogy, which is a lot more than you can say about the second.

1956
Directed by John Sherwood
Written by Arthur Ross
With Rex Reason (Dr. Thomas Morgan), Jeff Morrow (Dr. William Barton), Leigh Snowden (Marcia Barton), Ricou Browning (The Gill-Man), and Don Megowan (The... Lung-Man?)

Spoiler alert: high

Cardboard Science: I may be the dumbest man to ever walk the Earth

THIS ISLAND EARTH

In the aggregate, the science fiction mediocrity for all time.

1955
Directed by Joseph Newman (and, maybe, possibly, sort of... Jack Arnold)
Written by Franklin Coen and Edward G. O'Callaghan (based on the story "The Alien Machine" by Raymond F. Jones)
With Jeff Morrow (Exeter), Rex Reason (Dr. Cal Meachum), Faith Domergue (Dr. Ruth Adams), Russell Johnson (Dr. Steve Carlson), Robert Nichols (Joe Wilson), Lance Fuller (Brack), Douglas Spencer (the Monitor), Orangey (Neutron), and Regis Parton (the Mu-tant)

Spoiler alert: high