Dawson Casting: The main characters are played by 20 something actors.
Freddie Wong is Ted Wong's father, but the Wong brothers were born just a year apart! Depending on the time of year, they are actually the same age.
Most, if not all of the actors are in their 20s and 30s.
Lampshaded in the final episode of Season 3, when New Law tells The Law that he looks like a thirty-something year old man.
Defictionalization: Season 2, Episode 3 involves a game Ki made; High School Video Game: The Video Game High School Video Game. It's basically an 8-bit interactive version of Season 1. And it is entirely playable in Real Life, here.
Romance on the Set: Predicted by some fans, and later confirmed, Johanna Braddy (Jenny Matrix) and Josh Blaylock (Brian D) started dating during the production of the first season. They are now married! Plus in the episode 9, an after-match scene turns into quite non-movie style when it comes to their First Kiss.
Also has hints of Shipper on Deck: According to Benji Dolly (Games Dean) on the "Acting" podcast, co-director Matt Arnold was in casting from Season 1, saw Johanna and Josh's screen test, and said "We got our two, and I'll bet anything in the world those two (Johanna and Josh) end up together."
Separated-at-Birth Casting: Averted with the Wongs because they are brothers in real life, but Cynthia Watros really does look like an older Johanna Braddy.
Talking to Himself: Benji Dolly plays both Games Dean and his brother Sames. Note how both of them never have their face shown at the same time in S3E2...