Sergio Leone’s "Once Upon a Time in America" transcends conventional genre classifications, functioning as a sprawling cinematic meditation on the fallibility of memory and the evolution of the American gangster archetype across the 20th century. The film’s non-linear narrative structure, oscillating between the Prohibition era and the late 1960s, serves not merely as a stylistic flourish but as a deliberate exploration of how the past irrevocably shapes and often distorts the present. David "Noodles" Aaronson’s (Robert De Niro) return to a changed Lower East Side becomes a catalyst for a fragmented reconstruction of his history with Max Bercovicz (James Woods) and Deborah (Elizabeth McGovern), a history marked by both profound camaraderie and devastating betrayal.

Tonino Delli Colli’s cinematography employs a painterly aesthetic, utilizing expansive vistas and intensely intimate close-ups to evoke both the grandeur and the claustrophobia of the characters’ world. The film’s distinctive visual palette, shifting from the warm sepia tones of memory to the starker hues of the later timeline, underscores the subjective and often unreliable nature of recollection. Leone’s deliberate pacing and extended takes contribute to a sense of temporal displacement, mirroring Noodles’s own disorientation.

The performances are characterized by a nuanced exploration of character psychology. Robert De Niro’s portrayal of the aging Noodles embodies a profound sense of melancholic introspection, his physicality reflecting the weight of unresolved trauma. James Woods imbues Max with a volatile charisma that hints at the underlying ambition and moral ambiguity driving his actions. Elizabeth McGovern’s Deborah serves as an almost ethereal figure, an object of idealized longing whose presence haunts the male protagonists’ recollections.

The film’s diegetic and non-diegetic soundscape, masterfully crafted by Ennio Morricone, operates as a crucial element in evoking emotional resonance and thematic undertones. Morricone’s haunting melodies are not merely accompaniment but function as a sonic representation of nostalgia and regret, deeply intertwined with the film’s exploration of memory and loss.

The narrative structure, conceived by Leone and his collaborators, deliberately eschews a straightforward chronological progression. This fragmentation compels the viewer to actively engage in the process of piecing together the past, mirroring Noodles’s own struggle to reconcile his memories with the reality of his present. The film’s thematic concerns extend beyond the conventional tropes of the gangster genre, delving into existential questions of identity, the corrosive effects of time, and the elusive nature of truth as filtered through individual perception.

In conclusion, "Once Upon a Time in America" represents a significant departure from traditional gangster narratives. Leone utilizes the genre framework as a vehicle for a profound exploration of memory, loss, and the complex interplay between past and present. The film’s distinctive visual style, compelling performances, and evocative score coalesce into a cinematic experience that transcends mere storytelling, offering a poignant and often unsettling meditation on the human condition.