Zack Snyder is known for movies like 300, Watchmen, and Batman V Superman: Dawn of Justice, but among the many films he's directed, there are quite a few that never happened. Like with many writers and directors, there are sometimes movies that are discussed with studios and even other filmmakers but go unmade. Unfortunately, for Snyder, several of his ideas were never turned into movies.
Given the fact that he launched the DC Extended Universe with Man of Steel and Batman V Superman: Dawn of Justice, Snyder has been intricately connected to DC Films over the past few years. A significant part of that is because his planned 5-movie story arc for DC never came to fruition - and instead, his Justice League ended up replaced by a version that perverted the story and characters, thus leading to the famed Snyder Cut.
However, before and after his time with DC, there were several movies that Snyder could've potentially made but didn't for one reason or another. Interestingly, while some of these movies were only ideas that he floated, quite a few of them were ultimately made by other directors, albeit differently than how he would've done them.
Justice League & Its Sequels
The crux of Snyder's 5-movie arc stems from Bruce Wayne's Knightmare vision in Batman V Superman: Dawn of Justice. In this vision, the Earth as been decimated by Darkseid, the ruler of the planet Apokolips, with his forces and Batman being at odds with Superman, who commands his own army on Earth. Batman awakens from this vision to find a time travelling Flash warning him about Superman and that "Lois Lane is the key." Before he disappears, Flash begs Batman to find the others, referring, of course, to the members of the Justice League that he eventually recruits.
In Snyder's vision, audiences would have seen how Earth became this Knightmare of Bruce Wayne's: Darkseid kills Lois Lane, devastating Clark and making him vulnerable to the Anti-Life Equation, a plot thread that was setup back in Man of Steel. The film series would have ended with Batman dying, perhaps due to an Omega blast from Darkesid meant for Clark or Lois. Snyder also planned to introduce iconic Justice League members, like Green Lantern, and it was also going to be revealed that General Swanwick was actually J'onn J'ozz, the Martian Manhunter.
Of course, this plan was thrown out when Snyder and Warner Bros. parted ways during Justice League's production. Plus, Ben Affleck is no longer playing Batman and it's unclear if Henry Cavill will ever return as Superman. So while Snyder laid the foundation for this story and future Justice League sequels, they'll unfortunately never be made.
X-Men 3
X-Men 3: The Last Stand had a difficult time getting a director to commit to it. Bryan Singer, the director of the first two X-Men films, left to focus on developing Superman Returns. Among the many contenders considered for this position were Darren Arronofsky, who had just finished filming The Fountainhead alongside Hugh Jackman; Alex Proyas, who had a feud with 20th Century Fox's president at the time; Joss Whedon, who was in the middle of developing a Wonder Woman film; Matthew Vaughn, who signed onto the project briefly, and then Zack Snyder. Fox ultimately replaced Vaughn with Brett Ratner and filming began.
Snyder turned down the job because he was already tied to 300, although given his love of superheros, he might have taken on the role. Snyder's visual flair is one well suited for ensemble casts and action-heavy sequences. His use of speed ramping makes it easy for audiences to follow the action and they play out on the screen much in the same way comic panels to on the page. X-Men 3 was in production long before Snyder signed on with Warner Bros., however, and it marks the first of two occasions where a Snyder/Fox partnership might have happened - the second being a Wolverine film.
A full decade before Logan hit theaters, Zack Snyder had expressed interest in directing a Wolverine film but insisted on it being rated R. At the time, R-rated superhero films were not only rare but also less financially successful than their PG-13 counterparts. Examples of this from the early 2000s were Blade and Snyder's own Watchmen. Studios were initially hesitant to green light R-rated movies due to them being riskier box office bets, since parents would likely be unwilling to take their children to see them in theaters. Snyder could have potentially been slated to direct a X-Men Origins: Wolverine, but he was busy with Watchmen. Interestingly, Origins' screenwriter, David Benioff, intended the film to be R-rated, but it was changed to prevent box office losses, albeit unsuccessfully so.
Snyder at the helm of a Marvel/Fox production would have been a change of pace for the man who jump-started Warner Bros.' DC shared universe, and one can't help but wonder what Snyder would have done with Wolverine's character and story had he been given the chance, or what DC would look like had Snyder not stuck around as long as he had.
Heavy Metal 3
Heavy Metal is a 1980s adult animated movie that was based on the magazine of the same name. The magazine was known for its use of graphic violence, sexuality, and nudity, and it was supposed to serve as a foil for more mainstream comics that were bound by the Comics Code Authority. A Heavy Metal sequel was released in 2000 and a part part has been in various stages of development over the past two decades with David Fincher and James Cameron co-producing. Several directors had expressed interest in directing a segment for Heavy Metal 3, including Guillermo del Toro, Gore Verbiniski, James Cameron, and Zack Snyder. Unfortunately, it hasn't happened yet and is unlikely to in the future. After all, in 2014, Robert Rodriguez acquired the property's rights and planned on making a Heavy Metal TV series instead of a movie.
Legend of the Guardians Sequel
Legend of the Guardians: The Owls of Ga'Hoole was Snyder's first animated feature, and although it wasn't a huge success - earning $140 million based on an estimated budget of $80 million - he wanted to make a sequel. At the time, Animal Logic seemed interested in a sequel as well, but nothing ever manifested. Given that the studio and Snyder moved onto other projects - Animal Logic working on the LEGO Movie series and visual effects for the MCU and Snyder taking on the DCEU, hope a Legends of the Guardians sequel fizzled out.
SWAT
Samuel L. Jackson and Colin Farrell's S.W.A.T. was directed by Clark Johnson, but before he came on board, the studio approached several directors to make a movie version of the 1970s TV series of the same name. Among those directors were Michael Bay, John Woo, and Rob Cohen. Of course, Zack Snyder was also approached to direct and has stated that he was ready to do it, but he explained at the Vero Panel Director's Cut Event in 2019 that he envisioned a S.W.A.T. movie as "basically propaganda." According to Snyder, the studio had asked him to make a PG-13 rated S.W.A.T., something he couldn't envision and so passed on it. S.W.A.T. would have been Snyder's directorial debut and he joked that he talked himself out of what would have been an even bigger movie than Dawn of the Dead, his first feature film.
Movies He Hasn't Made (Yet)
Despite working with Warner Bros for so many years, Zack Snyder has movies with other studios in the works that haven't been made yet, including Army of the Dead, a version of what was supposed to be sequel to Dawn of the Dead but has since been rewritten and re-imagined as a standalone film. There is also a curious movie titled The Illustrated Man that is based on a collection of stories by Ray Bradbury. While Army of the Dead is expected to release on Netflix sometime in late 2020, The Illustrated Man has been on Snyder's radar as early a 2007.
Very little information has been revealed about the project in the years since the announcement and it's unclear why the film has been stalled for this long. However, it remains listed as one of the upcoming productions by The Stone Quarry, the company Zack and his wife Deborah established in 2004. Snyder has also announced he's working on an adaptation of Ayn Rand's The Fountainhead, a passion project of his, as well as The Last Photograph and a possible George Washington and/or Napoleon Bonaparte feature film in the style of 300. Despite his patch of bad luck, fans and audiences should rejoice at the prospect of future Zack Snyder films as he is showing no signs of stopping or slowing down.