The character's dual identities as Atlas and Fontaine has been subject to significant discussion and critical analysis within the context of BioShock's setting and themes.

The character's role as the final boss of BioShock is less well received, with much of the criticism focusing on his visual design as well as structure of the associated gameplay mechanics.

[3] The 2005 film Syriana inspired aspects of the backstory for Atlas/Fontaine, in particular his modus operandi of finding disadvantaged individuals through charitable initiatives like Fontaine's Home for the Poor and the Little Sisters Orphanage, an anathema to Ryan's objectivist worldview, only to cynically exploit them for his own ends.

[3] Aspects of his characterization was also inspired by the 1995 film The Usual Suspects, specifically its main antagonist Keyser Söze as well as a scene that revolves around a bulletin board.

[4] The developmental team went with Atlas/Fontaine as the final boss of BioShock, and the form the character takes for the fight visually alludes to typical classical sculptural depictions of Atlas.

[5] In this form, he is presented as a nude metal-skinned man who has injected himself with excessive amounts of ADAM, a genetic material that grants superhuman powers, severely altering his appearance to a grotesque vision of a god-like figure.

[6] Levine would openly express his regret over the design and implementation of the Atlas fight in the years following the release of BioShock.

[10] The character's original voice actor spoke like Freeman with a Southern drawl; this version of Atlas was featured in an internal critical playtest of BioShock which occurred in January 2007.

[10] For Fontaine, Hanover was instructed to perform with a Chicago accent and use J. E. Freeman's Miller's Crossing character Eddie Dane as an archetype in order to convey his intimidating tone.

[10] The recording lasted between four and five 8 hour days, as well as a few short supplementary sessions which he had to attend as a result of technical issues by caused the studio's mixing boxes.

[10] Hanover noted in an interview that he would have framed it differently if he had the benefit of hindsight, but appreciated that Levine's direction for him to speak that phrase in a consistently nonchalant manner was a "clever" decision creatively.

Atlas guides him to safety and claims that he is motivated to help Jack so that he could reach his wife Moira and son Patrick, who have been hiding out on a submarine in the Neptune's Bounty area, on his behalf.

As Jack makes his way through the city, he learns about Rapture's history and fate through recovered audio logs, genetically induced ghostly playbacks of past events, and radio messages from Atlas.

As a result of Ryan's strict ban of contact with the outside world in order to safeguard the secret of Rapture's existence, a black market in smuggled goods arose, which is dominated by a mobster named Frank Fontaine.

Fontaine's wealth, combined with his access to scientific breakthroughs from the Rapture-based scientists Dr. Brigid Tenenbaum and Dr. Yi Suchong, soon gained him enough power and followers to challenge Ryan for control of the city.

Ryan informs Jack that he was designed to obey orders from Atlas when addressed with a trigger phrase, then sent to the surface after the civil war in Rapture began.

Tenenbaum deactivates some of Jack's mental conditioning and assists him in breaking the remainder, including one activated by Fontaine that would have eventually stopped his heart.

Elizabeth has a momentary vision in response to the stressor, and realizes that Suchong is in his clinic guarded by Ryan's security systems that are keyed to repel Atlas and his men by their DNA.

Atlas orders his men to make arrangements for Jack to come to Rapture, and then delivers a fatal blow to Elizabeth, leaving her to spend her final moments with Sally.

None of the players indicated that they trusted Atlas as a welcoming party or guide to Rapture; one attendee described the character's voice as a "lecherous Colonel Sanders".

[14] IGN ranked Atlas/Fontaine 58th in their list of "Top 100 Video Game Villains"; they claimed that the character retains an "undercurrent of sympathy" in spite of his heinous actions, "a desperate man in a harsh environment, trying to cope with the suffocating ego of Ryan".