1. When Asgardian ship wreckage is shown floating through space, you can see Grandmaster's "leisure vessel" from Thor: Ragnarok.
2. Before sending Hulk back to Earth in Avengers: Infinity War, Heimdall says, "All-Father, let the dark magic flow through me one last time." This is a reference to what Loki says to Thor when he arrived on Earth in the Avengers.
3. The lamps in Wanda and Vision's room match the colors of their respective powers.
4. The old flip phone Tony Stark has is the one Steve Rogers left for him at the end of Captain America: Civil War.
5. When Iron Man uses his nano-tech suit, it even absorbs his sunglasses.
6. When Star-Lord tells the group to put on their mean faces as they're approaching a distress signal, Mantis actually changes her expression to fit his request.
7. Groot is seen playing a handheld game called Defender, an '80s arcade game in which the player must defeat waves of invading aliens.
8. In one scene, Peter asks Tony if he's ever seen Aliens. Later, Tony has Drax pinned to the ground and his gun resembles a Xenomorph, creating a visual similar to a classic moment from Alien.
9. When Star-Lord describes Thor as "not that good-looking," Spider-Man can't help but react with a confused expression.
10. In one scene, Mantis is shown positioning her hands like an actual praying mantis.
11. When Gamora stabs Thanos, her weapon doesn't have any blood on it, indicating that they're in a fake reality.
12. The spots of blood next to Gamora indicate that she isn't the first person who had been sacrificed in an effort to acquire the Soul Stone.
13. A blue Tobias Fünke can be spotted in The Collector's museum.
14. The weapon Iron Man chooses can be seen in the left corner of his HUD, which he uses immediately after.
15. When Doctor Strange uses the Images of Ikonn spell to create confusion, you can see the Soul and Power Stones light up when Thanos activates them to identify the real Strange and break free of his hold.
16. And the force from the Power Stone momentarily knocks Doctor Strange's soul out of his body.
17. In an early battle, Cull Obsidian's hand is cut off by a closing portal. Later, Obsidian shows up with a prosthetic hand.
18. When Dr. Strange hands the Time Stone over to Thanos, his hands are still visibly scarred and shaky from his accident.
19. As Thanos hastily leaves Wakanda, you can see the faint green sparkle from the Time Stone undoing his chest wound from Thor's Stormbreaker.
20. In the final scene when Thanos watches the sunrise, his armor is seen standing like a scarecrow, a reference to a moment from the comics.
