There are many things that rile up Star Wars fans about George Lucas' prequels, but perhaps the intense criticism can be summed up in five syllables: midi-chlorians. People didn't need an explanation of the Force, they didn't want an explanation of the Force, but as it turns out, you can only be a Jedi if these microscopic beings exist within your bloodstream or something along those lines. And if Lucas had his way, this wouldn't have ended with prequels, either.
In the book companion for James Cameron’s Story of Science Fiction — released in conjunction with the director's mini-docuseries on AMC — Lucas revealed his plans for Star Wars sequels that never came to be. Spoiler alert: If you hated the midi-chlorians, you probably wouldn't have been a fan of this new trilogy, had Lucasfilm not been bought out by Disney.
"[The next three Star Wars films] were going to get into a microbiotic world," Lucas said. "But there's this world of creatures that operate differently than we do. I call them the Whills. And the Whills are the ones who actually control the universe. They feed off the Force."
Sounds like he wanted to do an Osmosis Jones-esque adventure in the microscopic universe contained within the larger Star Wars universe. Nevertheless, the concept of the Whills didn't entirely die when Lucas gave up control of his company. When Jyn Erso first encounters Chirrut Îmwe on Jedha in Rogue One, Cassian Andor describes the blind man as one of the "Guardians of the Whills."
"Back in the day, I used to say ultimately what this means is we were just cars, vehicles, for the Whills to travel around in," continued Lucas. "We're vessels for them. And the conduit is the midi-chlorians. The midi-chlorians are the ones that communicate with the Whills. The Whills, in a general sense, they are the Force."
He readily admitted that most likely there would have been a ton of backlash, as there was with Phantom Menace, but even so, he'd still get to lay everything out on his own terms.
"I never got to finish," he said. "I never got to tell people about it... A lot of fans would have hated it, just like they did Phantom Menace and everything, but at least the whole story from the beginning to end would be told."