This well might be the first vampire movie to propose the idea that there are different "species" of vampires which have their own abilities and vulnerabilities, and which must be dispatched in different ways. This characteristic makes it different from other Hammer vampire movies, as does the casting of lesser-known actors besides Lee and Cushing. In addition, while Cushing as Van Helsing is very physical, and even swashbuckling at times (the climactic battle with Lee's Dracula in the first movie in the series being the most famous example), Captain Kronos is literally a swashbuckler, crossing swords with antagonists a number of times in the movie. There is even a plot surprise or two in Kronos that I didn't see coming, and some moments of pretty clever dialogue.
So, as many other reviewers have noted, this is one of the best Hammer horror movies, and probably the only reason it isn't more famous is that it lacks Cushing or Lee's presence. On the other hand, that's actually part of what makes it a really interesting movie. In any case, it is unjustifiably overlooked, and should be on the watchlist of any fan of British horror or vampire flicks.
So, as many other reviewers have noted, this is one of the best Hammer horror movies, and probably the only reason it isn't more famous is that it lacks Cushing or Lee's presence. On the other hand, that's actually part of what makes it a really interesting movie. In any case, it is unjustifiably overlooked, and should be on the watchlist of any fan of British horror or vampire flicks.