The burnt body of Anton Girdeux, the French terrorist with the flame thrower from the first game, can be found in the secret Agency lab morgue near the end of the game.
This is the only game in the series where Mara Aramov does not make an in-game appearance; she only appears in the cutscenes and multiplayer mode.
No recognizable buildings are visible in the New York City skyline during the final levels. Only the Twin Towers of the World Trade Center can briefly be glimpsed when Gabe breaks into the Pharcom Exposition Center, earlier in the game.
There is a hidden video 'Congratulations, Party Time!' that is unlocked by completing the game on hard mode. It shows the characters dancing on Club 32, which is a comic relief for the series tone of the game.