How bad is it? It's a pretty terrible rip-off of King Solomon's Mines.
Should you see it? Yes. It's amusingly bad.
In this Italian travesty, a college student in the 1930's seeks a lost diamond mine that no one knows about, except Nazis, Chinese gangsters, some English and Dutch guys and the local murderous tribesmen. There are scenes that make no sense, suggesting editing errors. There are enormous plot holes, such as the ending, where they walk off into the sunset... without food, water, compass, maps, or anything useful. There's a white actor playing a Chinese man and another playing the empress of an all-female tribe. The bad guys just give up when it's convenient.