Trivia: In the comics, Falcon has taken on the mantle of Captain America before.
Trivia: Robert Downey Jr. was the only member of the cast who was allowed to read the entire script.
Trivia: The man talking to Cap at the support group about his date is Joe Russo, one of the directors of the movie.
Trivia: A young man is shown onscreen towards the end with the others, and it's not immediately obvious who it is - it's Harley Keener, played by Ty Simpkins, the boy in Iron Man 3.
Trivia: Thanos' gauntlet bears a striking resemblance to the relic of the hand of St. Teresa de Jesus, one of the most important holy relics in Spain.
Trivia: During the Steve Rogers support group scene, the bald man with glasses and goatee is none other than Jim Starlin, the comics writer and artist who created Thanos.
Trivia: Spoiler! Falcon announces his arrival to Captain America with "on your left", the same phrase Cap taunted him with when they first met in Winter Soldier.
Trivia: The arc reactor that says "Proof that Tony Stark has a heart" is the gift Pepper made for Tony in Iron Man 1 after she removed his old reactor.
Trivia: One of the time-travel movies referenced by Ant-Man is "Hot Tub Time Machine", which featured Sebastian Stan, who plays Bucky in the MCU. In fact several of the films or franchises mentioned during the scene feature MCU stars. "Star Trek" had Chris Hemsworth in a small role in the 2009 film (If Inhumans still counts as MCU, then Anson Mount has been on Star Trek Discovery). Scott mentions 'Die Hard, ' which had Samuel L. Jackson in the third film. Interestingly, they don't mention Doctor Who, which has featured myriad MCU actors over the years, including Karen Gillan (Nebula), Christopher Eccleston (Malaketh the Dark Elf), and David Tenant (The Purple Man).
Trivia: Near the start, Okoye submits a report about an earthquake in the Atlantic, saying they should leave it alone. This is a potential tease for Namor the Sub-Mariner, ruler of Atlantis. This has been hinted at before, with a map in Iron Man 2 showing a point of interest in the Atlantic - the same map which flagged up Wakanda long before the official introduction of Black Panther.
Trivia: When Wasp appears to join the final battle, look to her right and you can see the Ravagers from Guardians of the Galaxy, including Kraglin (Sean Gunn), and even Howard the Duck.
Trivia: There are no inserts of any of the actors in the funeral scene at the end of the film. Everyone pictured is actually there. The Russo Brothers have called it, "The most complicated scheduling shot in the history of cinema." (Source: Film School Rejects).
Trivia: Despite her prominent billing, Brie Larson has only 10 minutes of screen time.
Trivia: Before the last battle Steve says "Avengers Assemble," a classic line from the comics which despite a few teases hadn't yet been said in the MCU.
Trivia: The number on Scott Lang's storage unit is 616. This is the same number used to refer to Earth Prime (the primary Earth 'continuity') in Marvel comics.
Trivia: Ken Jeong and Yvette Nicole Brown have cameos in the film. The two co-starred in the TV sitcom "Community," which "Endgame" directors Joe and Anthony Russo both worked on.