Al Adamson is one of the all time greats in the ridiculously bad horror movie genre. "Horror of the Blood Monsters" is basically a movie from the Philippines called "Tagani", with a whole additional plot wrapped around it featuring a scenery-chewing performance by John Carradine in a space ship.
In the beginning of the film you will be led to believe that the movie is about vampirism, but it is actually more of a journey into space so realistic you'll swear you are watching the NASA channel. OK, seriously, the scientific expedition which may remind you of the much earlier "Rocketship X-M", is so outrageously hokey that you will not be able to stop rolling around on the floor laughing. The expedition is led by John Carradine and two other guys named Willy and Bob. They have some sort of accident which forces them to land on this planet (which looks suspiciously like a globe of the Earth) filled with every sci-fi cliche known to man: beautiful cave women in bathing suits, cavemen with big teeth (the alleged connection to the vampire introduction), flying monkey (bat?) creatures on visible wires, lobstermen vulnerable to primitive wrestling holds, shots of two pet store size lizards wrestling as if they were dinosaurs, etc. None of that is that remarkable, but it was filmed in "Demonic Color" according to the box, which symbolizes the deadly 'chromic radiation' that endangers them all. Actually it is a filter making entire scenes look red, yellow, green, or blue. You will just love the 'special effects'.
The cast is perfect for the film and all engage in their individual pieces of rank melodrama with gusto, led of course, by the all time champion grumpy-old-man, John Carradine. This would have made an excellent MST3K. They just don't make movies like this anymore, which is a shame. This is one of Al Adamson's best (by which I actually mean worst), and I highly recommend it to bad movie buffs anywhere!