Sunshine and it's not even close
Sunshine is one of the best cosmic horror movies ever made too; if you think Sunshine was some hard sci-fi movie that weirdly switches genres at the end, you werent paying attention. The movie is setting that up from scene one and is steeped in cosmic horror/religious elements throughout. Pinbacker is the logical conclusion of what the movie established from the first scene
The overwhelming howling force of the sun dwarfs our protagonists' ship, a cosmic force that invades their nightmares, that draws those that watches its light into enraptured near-religious worship of the sun, a siren song that drives people to madness. What seemed like an out-of-nowhere third-act twist now felt like the logical endpoint of the clues and themes laid out by the movie from scene one
I can't think any other sci-fi movie since Alien and 2001 that makes space feel like such a hostile uncaring abyss. From the everpresent power of the sun, with only a shield and a single mistake between survival and obliteration, to the constant reminder of how fragile their resources and protection are against the void outside, Sunshine wraps its character drama and thrills in a sense of constant threat. It truly captures that aspect of cosmic horror, even without all the more subtly Lovecraftian elements.
Like these kinds of shots reminded me of The Void, especially once you consider the hypnotic almost religious pull the sun has Searle and the captain
A hostile uncaring environment, less like the exterior of a ship and more like the surface of some alien landscape, weird spacesuits that look more like oppressive diving suits to explore the abyss rather than the traditional outfits
The overwhelming howling force of the sun, with Searle madly yelling "what do you see" as if witnessing the unfiltered solar light as you're being consumed will reveal some unknown truths
Don't forget the sun invading their nightmares with shared dreams of falling toward its surface among at least two of the crew, or the movie diving head-long into "worshiping this cosmic entity changes you" territory by showing through Pinbacker what could have happened to Searle if he continued on his path of insane solar acolyte that has bathed in the sun's light
Pinbacker is presented in very inhuman ways that make it seem as if his reverence of the sun has distorted him. Our first glimpse is the jagged glitched video log. Then later in the viewing room, he's this gnarled desiccated silhouette that looks like a Slenderman-esque entity or an alien being, like something born from the light. His POV, and anytime we ever see him from other character's perspective, is through this wavering filter of eyes burned out by sunlight, as if his very presence is distorting reality
