James Clinton Howell, F.A.G. wrote:

MGS2’s mano-a-mano boss fights remixed formal elements from MGS1 specifically to frustrate the Scenario Map. No single fight in MGS2 copied MGS1 exactly. The resemblances were subtle. They worked on a subconscious level of pattern recognition that evoked memories of MGS1 while denying the catharsis that the patterns implied.

MGS2’s Fatman fight formally resembled Snake’s fight against Raven in MGS1. Both battles occurred in large areas gridded by industrial crates, and the player could defeat both bosses with similar strategies. Vulcan Raven constantly ran through his environment, and he was most easily defeated when the player laid Claymore landmines in his path. Fatman also went down easily when the player shot him while he recovered from a Claymore blast. As a formal conceit, MGS2 gave the player Claymores most abundantly around Fatman’s area. It even forced him to disarm and collect landmines twice on his way to the battle, just as he had collected Claymores before both Raven fights in MGS1.

Fatman's character design and fight patterns formally recalled Raven's while contrasting its content. Both men were physically the largest of their groups, yet Fatman had paunch instead of Raven's brawn. Raven had run through the level shirtless while toting an aircraft machine gun; Fatman skated under the weight of a full body bombsuit while plugging Raiden with a small Glock handgun. Raven had moved up, down, and side-to-side like a rook on a chessboard, and Fatman cut circles in the ground with his skates. Raven had forced Snake to run through a frozen, underground loading dock, while Fatman forced Raiden to run and freeze bombs across an elevated, open-air heliport.

MGS2 inverted the narrative results of each boss's defeat. After the player had beaten Raven in MGS1, Raven had slumped against a wall, helped Snake with his dying words, claimed that he would watch Snake from beyond death, and disappeared when his namesake devoured him. Fatman, however, slumped against a crate, antagonized Raiden with his dying words, and implied that he would only survive death when others remembered his legacy. MGS2 contrasted Raven's post-fight absence with Fatman's presence: the player physically hauled Fatman's body aside to defuse one final bomb. MGS2's narrative didn't even require Fatman's death. If the player had defeated him via non-lethal means, Fatman still breathed when Raiden proceeded with his mission.