Author Phobia: Tim Burton has been quoted as saying that he has a fear of monkeys. He changed the character of Thade from a white gorilla to a Chimpanzee for this reason (a chimpanzee is an ape, however).
Whereas other actors contending for the Leo Davidson role wanted to see the script before signing a contract, Mark Wahlberg signed on after a five-minute meeting with Tim Burton.
Paul Giamatti was a fan of the original series as a kid, so he jumped at the chance to play an ape when Tim Burton asked him. His agents suggested that he play a human character so as not to cover up his face in makeup, to which he said "If you tell them I want to play a human in this, I'll fucking kill you all."
Burton famously said he'd rather jump off the highest building imaginable than make a sequel to this.
Mark Wahlberg, while not regretting making the film due to working with Tim Burton, admitted that the film set the franchise back a bit.
Tim Roth, who played General Thade, has said he did not like the film's infamous twist ending, admitting that he could not explain its meaning or logic. Roth also didn't like working with Charlton Heston due to his NRA ties and admitted that if he had known that he would be sharing a scene with Heston he would have turned the movie down.
Helena Bonham Carter also expressed confusion at the ending during production.
Dyeing for Your Art: Tim Burton himself sustained an injury while demonstrating how he wanted one actor to fall sideways onto a safety mat. Unfortunately, his aim was a bit off, resulting in him cracking one of his lower ribs.
Executive Veto: Ari was first planned as an "ape princess", and the romantic interest for Leo, but 20th Century Fox vetoed any kind of human-ape romance, calling it "weird and unnatural." The veto stood, even after Tim Burton offered to make it platonic, or just implied. They still shared an on-screen kiss, however.
Hostility on the Set: Tim Rothwasn't happy about sharing a scene with Charlton Heston, due to his firm stance on gun control. While he managed to keep politics out of the workplace, he remarked that he wouldn't have done the film if he'd known that he'd have a scene with Heston. It's even more awkward when considering that a gun is the main subject of conversation between their characters in that scene!
"It was very difficult for me. On one level, there's the man, and he's my dad. But on the other level, the whole NRA thing is what it is now. I'm so against it, very vocally so. But it was inappropriate for the workplace. If I'm going to talk to him, I'll talk to him outside the workplace. So it was just two guys in make-up doing a scene."
Irony as She Is Cast: Charlton Heston's character explicitly points to guns as an example of humanity's destruction impulses and why it should be eradicated. This movie was made near the end of Heston's very talked tenure as president of the National Rifle Association.
In both the novel and the original movie, the orangutans rule the simian society and the chimpanzees are the liberal intellectuals. Many years of ape research later, finding orangutans are solitary while chimps are human-like in both organized society and tendency to aggression, the roles are changed in this (and retained in Rise of the Planet of the Apes).
Likewise, General Thade was originally planned to be a gorilla, like the gorilla hunters in the novel and the military in the original films. Rick Baker claimed to have convinced Burton to change him to a chimpanzee after research in The '70s and The '80s showed gorillas to be gentle vegetarians and chimpanzees the more vicious ones, though Burton also said that he chose to change Thade's species himself for different reasons.
Stillborn Franchise: The film's less than stellar critical reception put a quick halt to Tim Burton's involvement with the series and any sequels planned to this particular remake. That said, Tim Burton had no intention of making the sequel anyways, and the Sequel Hook was more for whoever else wanted to take a stab at it, though even that didn't happen. The reboot trilogy of the series that started in 2011 would end up overshadowing this film in critical and financial success.
Mark Wahlberg refused to wear a loincloth like Charlton Heston did in the original, because he didn't want to remind audiences of his underwear modeling.
Tim Roth asked Tim Burton if he could re-write some scenes to give his character a more frightening presence. Burton agreed and encouraged this idea.
Torch the Franchise and Run: Tim Burton has admitted that the ending was deliberately nonsensical so that, should any sequel occur, he wouldn't be the one who has to make sense out of it.
While in Development Hell, several people were attached at various points and vastly different scripts were considered. Had the project been greenlighted at any moment between 1988 and 1999, the movie would have been completely different from Burton's version (except for the apes' makeup: Rick Baker was practically attached from beginning to end). To recapitulate:
Adam Rifkin's idea (1988): Summarized as "Spartacus with apes", this would be an alternate sequel to the first film, set three centuries later, where the Apes have a Romanesque civilization and use humans as slave labor. Duke, a descendant of Taylor played by either Tom Cruise or Charlie Sheen would lead a human revolt; another subplot had the gorilla leader of the army staging a coup and murdering "a bunch of orangutans".
Terry Hayes' script, based on an outline by Oliver Stone (1994): A gritty reboot with little to nothing in common with the films or the novel, where a scientist played by Arnold Schwarzenegger travels back in time to 100,000 BC to find a cure for a plague that is decimating mankind in the future and finds himself in the middle of a war between primitive humans and advanced, gorilla-like hominids. It got as far as to get a $100 million budget confirmed and Phillip Noyce attached as director before being cancelled when Hayes refused to introduce more comedy.
Sam Hamm's script, in collaboration with Chris Columbus (1995): A closer movie to Pierre Boulle's novel, where Schwarzenegger would play an astronaut instead, and the apes lived indeed in a different planet and had a highly-advanced civilization. Almost all of it, however, would be either taken from once advanced ancient humans from the same planet that had wiped themselves out in a war in the distant past, or from TV transmisions from Earth that the orangutans had caught in secret before introducing all the advancements featured as if they were their own inventions, in order to justify their privileged status.
James Cameron's idea (1996): An Alternate History of the original saga, where the orangutans had been overthrown by the chimpanzees prior to Taylor's arrival and developed as a result a more advanced civilization. It would begin with original footage from the first film before introducing a second astronaut landing years later, and culminate with the new protagonist meeting Taylor (played by Charlton Heston, of course), now the old founder and leader of a tribe of intelligent humans.
Burton's own take went through different rewrites, having originally an Ari that was an "ape princess" rather than the daughter of a senator, Thade as an albino gorilla, Limbo making an emotional Heel–Face Turn instead of remaining a jerk, and Leo crashlanding in New York during his return to Earth instead of in Washington, D.C.
Burton wanted to give a "Cornelius-like role" to his friend Paul Reubens, but neither actor nor character was included in the end.
Djimon Hounsou turned down the role of Attar, because he was filming The Four Feathers.
Michael Bay was considered to direct twice - first when James Cameron's idea was proposed; that time, however, Fox chose Peter Hyams, only to later reject him, causing Cameron to leave the project. The second time was when the project was known as "The Visitor", but this time, Bay turned down the opportunity to work on Pearl Harbor.
Word of Saint Paul: From one of the actors (as opposed to the usual writer or director), Helena Bonham Carter stated that the ending was "...all a time warp thing. He's gone back and he realizes Thade's beat him there." When one considers that Leo's craft was still in the lake and could be retrieved, and that it was already shown to make it through time faster than Pericles' craft that Leo uses to return to Earth, this explanation makes sense.
, and people such as Peter Jackson, Chris Columbus, and Arnold Schwarzenegger were involved before it started to take off in 1999.