Animator Will Finn, who directed a bulk of the film, has spoken at length about how much he hated making this film and that he still has nightmares about it to this day. He hated the script and brought it to writer David Swift in the hopes of punching it up, later admitting that he agreed with Swift when he said, "You're never going to make a good movie with shit like this for writing!". He fought tooth and nail to keep the game sequence in the film because it was one of the few actual references to something indigenous of pre-colonial Latin America, and the higher-ups could give him no rational reason as to why they wanted it removed. He jumped ship late in production to return to Disney and had his name removed from the credits, leaving Don Paul and Eric "Bibo" Bergeron (and even an uncredited Jeff Katzenberg) to finish the job.
"Great crew - fantastic dedication of talented people but a doomed mess from concept on. I "directed" on it for almost 3 years but resigned ultimately. The movie has its moments but as a piece of entertainment it's utterly innocuous and forgettable. Yet unless you were there you'd never know the sheer madness and bloodbath it was to make. If they made a movie of the making of it it would be a cross between Mutiny on the Bounty and The Producers!"
Rick Farmiloe, who animated on Tulio for the film, didn't think much of the final film either.
"Part of my opinion of the movie is tied in with the crazy making of it. I have no particular fondness for it. It was a big missed opportunity as far as I'm concerned. The MAKING of it would make a much more compelling film!"
"For me there were two major problems with The Road to El Dorado. First, it was a period piece set in South America ó I thought at the time that that combination would be box office poison. There are certain settings and time periods that I donít think modern audiences are interested in, even if the film is fantastic. Second, the film didnít know what it wanted to be. Buddy movie? Action adventure? Romantic comedy? Musical? Historical tragedy? Romance? For adults? For kids? I think the project was like the proverbial elephant being examined by the blind scientists. Different directors, writers, and producers all tried to make different movies, and it ended up a mish-mash."
Creator Killer: After previously composing the The Lion King, the disappointing performing of this film botched the collaboration of composer Elton John and lyricist Tim Rice. They have not collaborated on any film since, and have mainly stuck to theatre. In addition, this was the first in the set of dominoes that made Dreamworks give up on hand-drawn animation until 2015, starting with Dawn of the Croods.
Enforced Method Acting: In a good way—Kenneth Branagh and Kevin Kline were actually in the recording booth together (which is rare; actors usually record their lines alone with someone else filling in the other characters) so they could play off each other and banter. It worked beautifully.
Troubled Production: As mentioned above, both director Will Finn and a handful of animators have unkind memories of this film, full of stubborn executives and a script they hated. Finn returned to Disney before the movie was even finished.
Urban Legend of Zelda: There's a rumor that in the original script, there were strong hints that Miguel and Tulio were a gay couple and Executive Meddling resulted in hints of homosexuality being removed and Chel being added, but the fact that Chel is included in rough model sheets and early test footage has debunked this rumor.
If this film had made its money back, we could have a whole franchise of them by now. They deliberately sprinkled the film with sequel hooks, and were already in the early stages of plotting out the sequels. One alternative ending to the film actually had them In Medias Res in their next adventure.
It was also going to be revealed at the end that the armadillo was an angel/spirit sent to help Miguel and Tulio. This makes sense when you think about it, considering all the crazy stuff that happens with it around, including pretty much flying through the ball hoop.
The movie was originally conceived as an R-rated comedy.
Chel was going to be a designated sacrifice victim, but the writers didn't want to show the city too soon.