Trivia: Robert Downey Jr. was the only member of the cast who was allowed to read the entire script.
Trivia: Samuel Jackson spotted that the eye patch his character wears in the movie switched eyes in the promotional posters announcing the movie in Los Angeles.
Trivia: During the film's climax, a young boy in an Iron Man mask is shown standing up to one of the Hammer drones with Iron Man swooping in and destroying the drone and giving the kid the credit. Following Spider-Man's inclusion in the Marvel Cinematic Universe, a fan theory suggested the young boy was Peter Parker, which Marvel Studios President Kevin Feige and Spider-Man actor Tom Holland would later retroactively confirm.Phaneron
Trivia: The first Marvel film released after Stan Lee's death. In tribute, the usual opening ident, which has the comic book characters in the Marvel Studios logo, instead shows multiple images of Stan Lee.
Trivia: Notice they don't play the lyrics with the "Iron Man" song in the closing credits. That's because the Black Sabbath song was not about the comic book Iron Man. There are many theories about what the song means, but the most popular is that it is about a man who travels to the future and sees the apocalypse. They couldn't use the lyrics to describe the Iron Man in the movie: He was turned to steel - In the great magnetic field - Where he traveled time - For the future of mankind. Now the time is here - For Iron Man to spread fear - Vengeance from the grave - Kills the people he once saved.
Trivia: Vin Diesel was given a special "Groot" version of the script that contained "translations" of what Groot was actually saying whenever he utters his one and only repeated sentence "I am Groot." This was done to help him deliver his dialog appropriately, since he would know exactly what point Groot was trying to get across with each line. Reportedly, only Diesel was given this version of the script - in everyone else's script, Groot's dialog is merely "I am Groot" over and over again.