This story was definitely a movie, but I've only seen it on TV. It was probably made in the late '60s or early '70s.
The plot is a crew of explorers launched on a mission to Mars. When they arrive they get equipped to explore (I don't recall if they used space suits or not). One piece of equipment was a freeze ray rifle.
The first bit of hostile Martian life was a plant with tendrils that tried to grab and eat one of the astronauts. The freeze ray handily settled that critter.
The next bit of hostile Martian life was a giant crab like creature. It was too big for the freeze ray to stop. So they needed to aim for smaller bits of the creature to stop it. With skillful shots, they were able to drive the crab critter off.
The last bit of hostile Martian life was a giant amoeba like creature. The freeze ray had no discernible effect on it. One or two astronauts got consumed. The rest ran back to the ship but not before one of them was touched & "infected" by the amoeba.
On the return trip the doctor/scientist figured out how to heal the "infected" astronaut. He ran current through his arm to drive off the amoeba infection.