Made on a legendary micro-budget of , the film’s "cheap" look often works in its favor, creating a grounded, documentary-like atmosphere.

Reviewers often split between those who find the film's refusal to explain itself exhilarating and those who find it impenetrable.

Beyond the physics, the film is a moral puzzle focusing on the erosion of trust, scientific addiction, and the human inability to control the consequences of such a discovery. Production and Visuals

“"The movie never looks cheap, because every shot looks as it must look... It is maddening, fascinating and completely successful." — Roger Ebert” Roger Ebert · 21 years ago

The film is dense with authentic-sounding scientific jargon and lacks traditional exposition.

“"It's not exactly a pleasant film to look at... But despite those issues, this is definitely an interesting viewing experience. It's unlike any film I've seen before." — Patrick J Mullen, Medium” Medium · Patrick J Mullen · 6 years ago

The second half of the movie becomes a "puzzle box" of overlapping timelines and multiple versions of the same characters, making it nearly impossible to fully grasp on a first viewing.

Most of the action takes place in mundane locations like garages, car parks, and office buildings, which heightens the sense of realism. Critical Perspectives