Ok. We'll put things in perspective. This was a low-budget movie for back in its time. Yes the early, early 60's. So, with that said...
I'm actually kind of impressed with this movie. Yes, there were lots of cliches', but I can also see the beginnings of Star Trek in this, of the Outer Limits, Space 1999. Lost in Space and so many others that have come after. I can see SO many Star Trek episodes in this that it's just freaky: The Gorn (with that Solorite alien... the sets with the marbled stone, dusty planet-scapes and beyond.)
There are reflections of Flash Gordon, of course...perhaps even Forbidden Planet (had this production had "that" budget).
Weighing things in total though, this was a pretty good movie and the art direction and even the effects were "ok" for its time. This movie was like a mix of the 30's 40's and 50's with a bit of intelligent writing thrown in the mix. Actually the acting (for the most part) wasn't half bad and the motivations were believable.
What impressed me the most was that there was a great deal of imagination involved in creating this. No fear, as it were. Pure Sci-Fi at its best and the thought that perhaps we, as mankind, aren't alone in this universe after all. Someone wrote and directed this movie with love, with a pure heart and with a vision (however stifled by the filters of time).
When I began reading Sci-Fi ,much of it from the 60s and even before, I was transported to the possibilities what "what could be". Phantom Planet took me back there again.