Incredibly immersive, the entire enclosed spatial feel relies on a techno-dystopian overcast signified by the somber use of darkness. The dingy lighting is constantly shifting due to fluctuating lumen levels, contrasting the natural brightness of the outside world. This difference comprehensively develops a shaded underground civilization because artificial light is unreliably uneven, and diffusing the glow of bulbs or lanterns across a wide area inevitably weakens the candescent output. Director Toshihisa Yokoshima combines cel-shaded 3DCG with the subtle movements of 2D animation, exhibiting mastery of motion mechanics. It's widely known that CGI generally boasts a less believable series of incremental human-like gestures, not a deterrenthere whatsoever. The animators have compensated for their inability to show expressions since everyone is wearing a weighty mobility suit protecting them from the aboveground dangers. Namely fiery ash ready to melt flesh, a post-apocalyptic survival narrowly avoiding extinction. Creative visual language such as creating outlines in the soot deposits on their helmets parallel emotions, allowing the audience to keenly search for other hints in the frame that substitute for dialogue disconnected from a face, which would dictate our impression had it been used.

Fuyu and Aki vow to travel outside and bask in the glory of creatures of times past, but unbeknownst to them, Earth is in ruins. Aki has the opportunity to discover another reality after a brief time skip when she joins a salvaging team hoping to describe the image of an actual sky to Fuyu. The thematic diversity ranges from optimism underscored by a sense of denial and the legitimate basis for their hesitation, evoking unease when the percussion tracks creep. Aesthetics supplement all of these atmospheres or moods, inky art complementing the grainy backgrounds. Rendering is phenomenal, with colored compositing for distinction, possibly representing specific symbolic imagery rooted in ambiguity, despite the film's final intentions. Cocolors emerges as a flexible metaphor for curiosity, your experience will always vary.