Dustin refers to the arcade game Dragon's Lair (1983) as "overpriced." Dragon's Lair was the first arcade game to charge $0.50 (even $1.00 in some markets) per play, breaking the $0.25 norm.
When Mr. Wheeler (Joe Chrest) asks Mike (Finn Wolfhard) if he'd jump off a cliff, Mike doesn't answer. In Season 1, Mike did jump off a cliff for a friend (albeit under threat from some bullies).
In an interview, Joe Keery (Steve) said that someone actually wrote Steve Harrington's fake college essay to use while filming the scene in Steve's car. He and Natalia Dyer (Nancy) couldn't stop cracking up because it was a "horrible, horrible, horrible essay."
When we first see Mad Max (Sadie Sink) skateboarding, she flips up her board, revealing a design that closely resembles the design of the Hoverboard from Back to the Future Part II (1989).
Season 1 drew some criticism for the way in which the return of Will Byers (Noah Schnapp) got all the attention, while the death and continued disappearance of Barbara 'Barb' Holland (Shannon Purser) was almost glanced over. Barb had become popular with many fans who were frustrated that her death in season one did not get a proper closure, and started petitions like #JusticeForBarb and "#WeAreAllBarb. These led to the makers addressing the character's disappearance in season 2.