Two years before Man of Steel ushered in the DC Extended Universe, Warner Bros and DC Comics released Green Lantern, the Emerald Knight's first theatrical movie, which was intended to kick off a new DC franchise. Unfortunately, the ring slinger's movie was met with mostly negative reviews and barely made back its budget. Its star Ryan Reynolds has since found his superhero happy place playing Deadpool, and looking back, he realizes that the reason Green Lantern failed was because it went into production before there wasn't a firm grasp on what the movie was supposed to be. As Reynolds put it:
Well it's simple: Deadpool always knew what it was. With Green Lantern, I don't think anyone ever figured out exactly what it was. That isn't to say the hundreds of men and women didn't work their fingers to the bone to make it as good as possible. It also fell victim to the process in Hollywood which is like poster first, release date second, script last. At the time, it was a huge opportunity for me so I was excited to try and take part in it.
Ryan Reynolds provided this explanation to EW, highlighting how although there were a lot of people working hard to make Green Lantern successful, Warner Bros was more concerned with releasing the movie rather than making sure the script was perfected before starting. That meant there was never an opportunity to nail down what the movie's tone was supposed to be, making the final product feel generic. Deadpool, on the other hand, knew what it was from the beginning: an R-rated, violence-filled, profanity-packed, hilarious movie that faithfully adapted the tone of the Merc with the Mouth's stories from the comics. To be fair, spending more than half a decade in development hell leaves a lot of time to iron out those details.
This isn't the first time Ryan Reynolds has publicly admitted that Green Lantern didn't work well as a movie, and it probably won't be the last. However, the actor has also said several times that he doesn't regret taking the Hal Jordan role, and would even take it again if he had to do it all over. Still, now that he's comfortable playing Deadpool over in the X-Men world, it's easier for him to look back on that Green Lantern time and pinpoint all the mistakes made along the way.
Although Green Lantern failed to launch its own series, the Emerald Knight's time on the big screen isn't over. Now that the DC Extended Universe is launched, the Green Lantern Corps reboot is scheduled for release in 2020, and it will feature multiple primary human Green Lanterns. There is also a rumor that a member of the Green Lantern Corps will show up in Justice League next year for a key sequence, so even though the universe where Ryan Reynolds' Hal Jordan was flying around won't ever be revisited, the mythology is receiving a second chance at wooing moviegoers.