Ray Gunn director Brad Bird explains why the Netflix sci-fi film took 30 years to make.

Netflix’s upcoming animated film follows Ray Gunn, the last human private detective in a futuristic world filled with aliens, featuring the voices of Sam Rockwell and Scarlett Johansson. For Bird – the director of The Iron Giant (1999), The Incredibles (2004), and Ratatouille (2007) – Ray Gunn is a passion project he has been working on since the late 1990s.

During an interview with ComicBook at San Diego Comic Con, Brad Bird says that Ray Gunn took 30 years because getting its ambitious balance right wasn’t easy. The story stayed the same, but refining how it was told and making its characters feel genuinely human required patience and precision. Read his full comments below:

On a broader level, it’s the same movie, and it has the same characters and the same ending and the same sort of structure. But how information was delivered shifted, as it always does when you’re making a film. You know what points you want to make, whether they’re plot or character things you want to say, but oftentimes, where you say them changes. You find different contexts to say them in a way that makes them more effective. I’m really happy with it. I mean, everyone rallied, and it was an ambitious film, meaning it was scary. When people first got involved, they were like, “Oh, jeez,” because the margin for error was narrow on it, narrower than something like The Incredibles. It was easy to do too little, and it was easy to do too much, and it had to be right in there. And at first, that’s daunting because it’s challenging. You want to explore it, and you want it to be caricatured and take advantage of the medium. But you also want the audience to feel emotional about the characters when you want them to be… it’s not like broccoli. It’s a fun movie to watch, but there are moments where you need to believe that the characters are real beings with the past, present, and future.

Another reason it took Brad Bird 30 years to make Ray Gunn is that securing its massive $150 million budget was difficult. For decades, no traditional studio was willing to put up the money, and Netflix was the only company that ultimately gave the project a green light and made it a reality.

Directed by Brad Bird, who co-wrote the script with Matthew Robbins, the animated movie combines elements of neo-noir, sci-fi, and mystery – following the titular private eye Ray Gunn (Sam Rockwell) in Metropia, a gigantic city in an alternate future as seen from 1939, as he is drawn into a case involving aliens, murder, and a multimedia star named Venus Nova (Scarlett Johansson).

The animated film also features the voices of Tom Waits as Eyera, Ray’s alien colleague, and Patton Oswalt (Ratatouille) as a hologram alongside Kathryn Hunter, John Ratzenberger (The Incredibles), and Jamie Costa. Scarlett Johansson voices Venus Nova, a “famous pop star struggling from a scandal that threatens to destroy her career — and may even cost her life.”

Ray Gunn is set for a release on Netflix on December 18, the same day that Dune: Part Three and Avengers: Doomsday are scheduled to release in theaters. Ray Gunn will also receive a limited theatrical run to qualify for Oscar consideration, with Bird already winning two Oscars for Best Animated Feature – Pixar’s The Incredibles (2004) and Ratatouille (2007).

Despite landing on one of the year’s busiest release dates, Ray Gunn shouldn’t be overlooked. Between its remarkable 30-year journey, Brad Bird’s proven storytelling, and a cast packed with familiar voices, it has all the ingredients to stand out. Whether you’re watching from home or heading to theaters, Ray Gunn is one worth making time for.