Cthulhu is an intense and atmospheric horror-fantasy movie released in 2007, directed by Dan Gildark and written by Grant Cogswell. The film draws heavily from the compelling lore created by the masters of cosmic horror, chiefly H.P. Lovecraft, yet opts to develop a unique tale rather than a direct adaptation of the writer's works. A mesmerizing blend of horror, thriller, and drama elements, the movie is set in the Pacific Northwest, specifically in a foreboding coastal town named Rivermouth.

The movie's protagonist, Russell Marsh (Jason Cottle), is a gay history professor living in Seattle. Following the death of his mother, Russell is drawn back to his estranged family and the eerily captivating town in Oregon where he spent his most formative years. At its core, the narrative makes a profound exploration of Russell's strained relationship with his family. Dysfunctional family dynamics play out, creating a human drama that is as fascinating as it is relatable.

The film does an impressive job of blending personal and intimate struggles with the grandiloquent cosmic horror themes. Russell not only has to battle his father's stern disapproval but also must unravel the sinister mysteries lurking within his hometown - secrets that cast long, menacing shadows that touch upon the chilling realm of the supernatural and cosmic terror, reminiscent of Lovecraft's mythos.

The word 'Cthulhu,' referenced in the title, is an entity from H.P. Lovecraft's fictional universe – an ancient cosmic deity associated with themes of existential dread and inconceivable horror. However, it this movie, the word is more a thematic symbol than a literal representation. The film serves up a tantalizing platter of pre-apocalypse tension – the continual sense of impending doom and eeriness is persistent throughout.

Cthulhu balances drama, horror, and thriller elements to create a narrative that is atmospheric, brooding, and intensely unsettling. The slow-building tension is infused with an existential dread that so defines Lovecraft's work. A significant part of the movie's horror comes from the slowly escalating sense of impending doom, which keeps you on the edge of your seat.

The film expertly highlights the theme of isolation, both in terms of Russell's personal alienation from his family and society, and the geographic isolation of the town itself. The coastal location, with its stark beauty and inhospitable terrain, serves as an ominous backdrop. The cinematographer, Sean Kirby, has done a remarkable job at capturing the chilling beauty of the coastal landscape, making it a character in its own right – a remote outpost perched at the edge of the world, huddled against the unknowable terrors of the sea.

The performances are solid too. Jason Cottle delivers a layered and coinvolving performance as Russell Marsh, while actors like Cara Buono and Scott Green contribute admirably to the overall depth of the acting crew.

Cthulhu isn’t a conventional horror movie by any means. It relies more on the use of atmosphere, discomfort, and dread than on cheap jump-scares. There is limited gore, and the horror is more psychological than physical. Shared in a partly non-linear narrative, with intense dream sequences and flashbacks, the film is stylishly shot and has a somewhat esoteric feel to it.

The film isn’t merely a horror/thriller; it also takes a look at societal issues of homophobia and religious zealousness, adding another layer to the narrative. Fans of Lovecraft's eldritch horrors – or horror fans in general – will find a lot to appreciate in this movie's mysterious and intense plot.

In summary, Cthulhu is a deeply atmospheric, moody, and unsettling film that deftly combines the personal dramas of its protagonist with the impending threat of cosmic horror. This slow-burning thriller manages to create an engaging and creepy work of horror fiction that leaves a lasting impression. If you're a fan of Lovecraftian horror or enjoy a more psychological and atmospherically rich approach to fear, Cthulhu may be exactly what you're looking for.