These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Another piece, "Snake Shake", ended up being cut from the ending, but it's still catchy as hell.
"Funny Aneurysm" Moment / Harsher in Hindsight: Snake lands his glider on one of the Twin Towers of the World Trade Center. It'll still be there in 1997, but the plot also features terrorists hijacking a jet airliner and then suicidally crashing it into a New York skyscraper in order to protest U.S. foreign policies. Ouch.
For a brief moment, it actually looks like the hijacked airplane is flying toward the World Trade Center.
Jerkass Woobie: The President. He's far from admirable, but it's hard not to feel bad for him when he's being tortured and brutalized by the Duke and his thugs, and it's hard not to cheer for him when he finally gets his revenge on the Duke at the end.
Upon further review, it is worth pointing out that in the original Snake was more of an opportunistic Anti-Hero with hints of a Jerk with a Heart of Gold; dangerous and resourceful, but not so ridiculously Bad Ass as the sequel made him.
That said, everybody inside New York has heard of him and heard rumours of his death. Considering that nobody ever comes out of there and that the only news updates that anybody would get is from new prisoners, Snake must have been involved in something major (possibly the Noodle Incident in Kansas City where Brain abandoned him) to have people know who he is.
Nightmare Fuel: The fate of the girl in the Chock Full O'Nuts coffee shop - it's implied that the Crazies eat her after catching and dragging her down to her doom out of camera range. In a weird way it's even more chilling when you remember that the actress playing her, Season Hubley, was Kurt Russell's wife at the time.
Snake Plissken as a character has received this in later years, due to being a strong influence on Solid Snake from the Metal Gear series.
Vindicated by History: It made a respectable splash in the cult sense when it was first released in 1981, but wasn't considered a classic by any stretch of the imagination. It has gained much more recognition over the years, mainly due, no doubt, to its influence on other media, with Metal Gear Solid, ReBoot, and The Grim Adventures of Billy & Mandy being only a few examples.
Visual Effects of Awesome: The visual effects hold up, even though it's a 1981 film. It's hard not to get chills when a dark, nearly lightless Manhattan is revealed.
Particularly notable is the computer image of New York, which is actually a practical effect. What you're seeing is a model of the city with a grid pattern of reflective tape.
The Woobie: Snake. Not so apparent in the movie, but I dare you to read through the Novelization and not see him as one.
Jerkass Woobie: Even in the movie, Snake is not really someone who you would call a Knight in Sour Armor. But let's take a look to his background: he gets betrayed by the same goverments he believed in during the "Leningrad Ruse" (where he lost the use of his left eye) and then all his country is turned into a totalitarian police state, with his parents being murdered by the police in the process. Wouldn't you be a bit sociopathic after that? He does, however, hold a loose code of honor and humanity and he can also occasionally step in the Jerk with a Heart of Gold territory.