Horrors of Spider Island is a classic horror film known for its unique blend of suspense, horror, and adventure. This 1960s cult classic is a perfect illustration of the era's love for thrilling tales full of suspense and haunted scenarios.

The plot of Horrors of Spider Island unfolds dramatically when a plane crash-lands on a deserted island. The group of survivors are all members of a dance troupe en route to Singapore for a performance who find themselves stranded in a remote territory with little understanding of the lurking dangers.

They soon encounter a horrifying slow-paced predator- a massive, fierce spider. The eerie crawlies are not the only inhabitants of the island, but unknown to the survivors, the island is also fraught with other spooky elements which make their survival extremely treacherous.

Their predicament worsens when Gary, the manager of the troupe, turns into a human spider after being bitten by the monstrous creature. This instills an unimaginable fear in the hearts of the all-female troupe, and the story is primarily centered on their struggle to survive on the deserted and uncanny island filled with horrifying surprises.

The eerie setting of the deserted island is incredibly omnipresent, supplementing the horror element of the film. As the survivors explore their unusual surroundings, the audience is taken on a nerve-racking journey where the foreboding dangers of the island are revealed slowly and steadily.

The narrative’s twist lies in the characterization of Gary, an otherwise usual manager whom the troupe trusts and relies upon, morphs into an unsightly and scary human-spider sending waves of horror amongst the troupe. The tantalizing suspense surrounding Gary’s transformation and what it signifies for the women castaways forms a central theme of the Horrors of Spider Island.

The cast performances, under the adept direction of Fritz Böttger, are able to successfully convey the essential terror and suspense of the plot. Gary, played by Alexander D'Arcy, brilliantly adapts his portrayal from a calm, reassuring figure to a terrifying creature of the night. His performance sets the tone for the hectic and horrifying ordeal to follow, making the audience wholly empathetic of the survivors' situation.

The title of the movie itself is enough to send chills down the spine, and certainly, the film lives up to its name with constant reminders of lurking dangers across the island. The terrifying encounters with the giant spider and the subsequent horror thriller sequences manage to keep the viewers at the edge of their seats.

The film's distinctive technique lies in its combination of classic horror tropes and unexpected plot developments. It expertly uses the often claustrophobic jungle setting to enhance the horror aspect of the film. The use of darkness and shadow further compounds the creepy atmosphere.

Horrors of Spider Island is not just a horror film but also a journey that underscores human survival instincts, camaraderie, fear and the will to endure in the face of eerie and unceasing dangers. Whether they manage to breaking free of the island's clutches and return to civilization becomes the pressing question that races the viewers’ heartbeat throughout the course of the film.

What sets Horrors of Spider Island apart from the other classic horror movies is its ability to weave a gripping tale of survival that is as fearful as it is compelling. While it contains all the elements of a traditional horror film, at its heart, it’s a story of survival against incredible odds, human adaptation, and resilience even in the face of such adversities — a factor which makes it stand out from other horror films of the time.

To sum it up, Horrors of Spider Island can be a delight for fans of old-school horror movies. While it evokes an ambiance of creepy suspense, it also offers a rich plot with strong performances from the cast. This film, under the expert direction of Fritz Böttger, has ensured its place in horror cinema as a timeless classic. From its portrayal of suspense and fear to its spine-chilling moments, Horrors of Spider Island guarantees to keep you on tenterhooks from beginning to end. In the end, it transforms from merely being a film into an enduring cinematic experience.