There's a George Lucas reference in Star Wars canon, and most of them are pretty easy for fans to spot.
However, there are some small references in Star Wars Jedi: Fallen Order which may have gone over players' heads the first time through. For instance, there are a number of indicators that both Darth Maul and General Grievous' actions helped set the plot of Star Wars Jedi: Fallen Order into motion, and many of the locations characters mention offhand were featured in the newest trilogy of theatrical Star Wars movies.
One of the best Easter eggs in Star Wars Jedi: Fallen Order, however, references the creator of Star Wars himself, George Lucas. During the section of the game in which Cal Kestis is ing his Jedi Padawan training, his master Jaro Tapal can be heard shouting at him to move "Faster! More intensity!" This is a direct reference to how Lucas would direct his actors on set.
According to Carrie Fisher during Star Wars: The Force Awakens' press tour, Lucas would often tell them to move "Faster!" and "More intense!" By including this dialog from the movie's original director in Star Wars Jedi: Fallen Order, it's almost as if the developers at Respawn Entertainment wanted their players to subconsciously feel as if they were being trained in the ways of the Force by Lucas himself. At the very least, they clearly felt as if his direction is perfectly suited for someone trying to teach a young child how to run across walls.
From a surprise Darth Vader cameo to featuring locations and characters from Star Wars: The Clone Wars animated television show, Star Wars Jedi: Fallen Order not only provided longtime fans of the franchise with a plethora of secrets to uncover but also gave them a quality single-player Star Wars experience with a coherent, enjoyable story, something many fans were likely worried they would never get again after previous slew of multiplayer-only Star Wars video games. Thankfully Respawn Entertainment left room for a sequel, so hopefully the next entry in the Star Wars Jedi: Fallen Order series will contain at least as many hidden references (and as much engaging swordplay) as the first one did.