1. The handheld game Groot is playing is called Defender, an '80s arcade game in which the player must defeat waves of invading aliens.
And Peter probably gave it to him!
2. There's a blue Tobias Fünke visible in The Collector's museum.
The Russo brothers, who directed Avengers: Infinity War, also directed episodes of Arrested Development in the past.
3. This image of Tony Stark on the news is actually a photo of Robert Downey Jr. from the Spider-Man: Homecoming red carpet premiere.
4. 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 first Avengers movie.
5. Rocket seems to have a thing for limbs. In Guardians of the Galaxy he jokes that he needs some guy's prosthetic leg and in Avengers: Infinity War he asks Bucky, "How much?" for his new arm that Shuri built.
6. Rocket also has a thing for eyes. He mentions taking eyes in both Guardians of the Galaxy movies, and he gives an eye to Thor in Avengers: Infinity War.
7. The shirt Peter Parker is wearing as he hops off the school bus reads, "Lettuce, the taste of sadness."
8. The old flip phone Tony Stark has is the one Steve Rogers left for him at the end of Civil War in case he ever needed him.