I think I saw this as a kid. I think I liked it. That would make sense because this film seems to be aimed strictly at kids. I watched it again a couple of years ago. The film really has a unique flavor to it. I picture the writers sitting down and writing a script for a comic book, in the sixties. Remember some of those? - like, Total War and MARS Patrol, some of those. The plots had to do with the invasion of the USA by an army using futuristic weapons. There were also the comic books published by Titan, called the THUNDER Agents. These were well illustrated, superior comic books for the time.
So, the writers write the script for BATTLE BENEATH THE EARTH, but instead of having it illustrated as a comic book, it's made into a film. That's my take on this. A lot of the stuff here and some scenes would be OK in a sixties comic book, but come across as a bit whacky in a film. Case in point, the first scene in Las Vegas (not really Vegas, but let it go): one of the main characters, a scientist (Peter Arne), is pressing his ear to the pavement and ranting about ants beneath us. He's carted off to the loony bin because he's behaving like a complete lunatic. Later, when the military becomes aware of the plot against the USA, this scientist is perfectly rational. This odd and conflicting behavior may work in a typically over-the-top comic book for kids, but makes little sense within the framework of a film.
Also, the extent of U.S. military might in this film seems to be one squad of soldiers (usually led by hero Kerwin Matthews). What, are all other soldiers and tanks deployed in other countries at the moment? The Chinese leadership seems to have been taken over by Caucasians in this version of Earth (what, no Oriental actors around?).
There is entertainment to be found: the Chinese have developed heat ray weapons and a special rock-melting/boring machine while the U.S. was busy with outer space technology; when the U.S. soldiers fire their rifles, the Chinese simply point what looks like a flashlight and Sssssssss - yyyahhhh!!! So, there is some similarity to the James Bond pictures of the time. It's just a little more goofy. Finally, I didn't understand how one atomic blast would take care of all of the enemy, considering that there were 3 tunnels, each about 500 miles apart. Comic book logic? Why not? Oh, and, hey, didja know - you can avoid an atomic blast by merely running for about 10 minutes. BoG's Score: 6
yyyahhhh!!!