Time Warner (TWX) has recently made some big moves toward creating its unified DC Cinematic Universe to rival Disney's (DIS 0.61%) version of Marvel's Cinematic Universe.

It signed on Ben Affleck as Batman and Gal Gadot as Wonder Woman -- two questionable casting choices that have raised doubts regarding the ability of an upcoming Batman vs. Superman or Justice League movie (as my fellow Fool Tim Beyers calls it) to rival Marvel's Avengers franchise.

The Justice League as depicted by Jim Lee. Source: DC Comics.

Therefore, let's take a look at three things that Time Warner and DC absolutely must get right for its new Justice League movie to succeed.

#1: Why so serious?

My first concern with DC is that the movie adaptations of its comic book heroes are too glum. The dark and serious approach was appropriate for Christopher Nolan's Batman trilogy, but it didn't fit Superman.

In my book, Zack Snyder's The Man of Steel suffers from very unfavorable comparisons to Richard Donner's Superman I and Superman II. Snyder's Superman was simply Donner's version with all the humor, life, and charm drained out of it. Snyder replaced those essential qualities with lengthy, mind-numbing CGI sequences.

"Why so serious, Henry?" Source: Comicbook.com

Another critical problem with Snyder's The Man of Steel was that it wrote Clark Kent (as we usually know him) out of the story until the last scene, when he comes to The Daily Planet with Lois Lane already aware of his secret identity. That twist eliminated the future possibility of those charming scenes in Donner's films where Christopher Reeve, a superior Man of Steel than Henry Cavill, effortlessly transformed from Clark into Superman.

Meanwhile, Nolan's trilogy was obviously not built to be integrated into the rest of the DC Cinematic Universe. Nolan and screenwriter David S. Goyer purposely eliminated the more fantastical, circus-like elements of the Batman universe, replacing them with a military-industrial theme grounded in reality. Although that theme was a key factor in the success of the Dark Knight trilogy, it also eliminated the possibility of Superman or alien invaders flying into Gotham City.

In this regard, Tim Burton's vision of Gotham City and its villains came closer to the comic book version with Batman (1989) and Batman Returns (1992). Unfortunately, Burton took so many creative liberties with the core characters that he alienated the comic book fan base.

That delicate balance of reality and fantasy is something that Marvel has done better than DC. The Avengers franchise ties together these characters with SHIELD, seamlessly blending more "realistic" characters such as Iron Man with alien invaders. In the comics, the Justice League never seems like a cohesive group -- one minute Batman is fighting thugs in the street, and the next moment he is being whisked away into another dimension to fight Darkseid.

#2: Bring in the writing and directing teams from the animated series

To achieve that balance between reality and fantasy, Time Warner needs a new writer and director for its Batman vs. Superman or Justice League film. The film, in its current form, will reportedly be written by Goyer and directed by Snyder -- which means that it could suffer from the same lack of charm and overuse of CGI that plagued The Man of Steel.

Goyer is also a comic book writer, but in film he keeps things grounded and realistic. Snyder, who also directed Watchmen and 300, excels at recreating comic book scenes panel by panel, but his films are generally humorless, noisy affairs.

Superman vs. Batman in animated form. Source: Collider.com

To solve this creative conundrum, DC should tap into the writing and directing staff for its animated series and video games instead. Paul Dini, one of the writers of Batman: The Animated Series, Justice League Unlimited, the acclaimed Arkham games, and ABC's Lost would be my top pick.

The universe that Dini has helped create represents a world where reality and fantasy are perfectly balanced, and writers like him would be the ideal people to properly merge DC's core comic book franchises with each other.

In addition, writers from the animated series know better which popular comic book storylines to draw from. For example, Tower of Babel, a Justice League story arc written in 2000 by Mark Waid, would translate very well to the big screen, since it showcases Batman's distrust and intellectual superiority to his mostly super-powered allies. Dark Knight Over Metropolis, written by Jerry Ordway, Dan Jurgens, and Roger Stern in 1987, also provides excellent material to properly define the love-hate relationship between Batman and Superman -- especially since it introduces the kryptonite ring Batman occasionally equips when Superman occasionally loses his cool.

#3: Don't rush things along simply to catch up to Marvel

Last but not least, Time Warner shouldn't hastily assemble its team of superheroes simply to catch up to The Avengers.

Ben Affleck might make a fine Batman, but wouldn't it be ideal to at least give him a new solo film to redefine his character to better fit in with the new Justice League? Henry Cavill also needs another dedicated Superman movie to show us what he can do with the Clark Kent role as well.

Meanwhile, Wonder Woman needs a solo film of her own to accomplish two things -- reboot Wonder Woman's story, which is nowhere as familiar as Superman and Batman's origin stories, and introduce movie viewers to Gal Gadot, an unfamiliar actress who has been criticized as being too thin and petite to play a warrior princess of the Greek Amazons.

Gal Gadot is the new Wonder Woman. Source: Geekbinge.com

The Avengers generated $1.5 billion in global box office sales because Marvel was extremely patient in building up the franchise. It let Nick Fury appear in small cameos to let audiences know that something much bigger was on the way. It's likely that Time Warner, seeing that big $1.5 billion figure compared to Man of Steel's $663 million, figured that it would skip all of that teasing with an earlier Man of Steel sequel that it could hype as a Justice League movie or prequel. If the film is successful, it could follow that up with individual sequels for Superman, Batman, and Wonder Woman.

Unfortunately, jumping straight into a Justice League movie in 2015 would be an all-in bet on the future of the DC Cinematic Universe. If it is a commercial and critical success, it could help DC catch up to Marvel very quickly, but if it bombs, it could cause another film reboot of all of the main characters involved -- ironically similar to what DC has been doing repeatedly in its comics to clean up over 70 years of continuity problems.

A final thought

Don't get me wrong -- I'm a big fan of DC comics and would love to see a proper Justice League film materialize one day. However, I'm afraid that Time Warner has gotten too far ahead of itself, and lacks Marvel's organized discipline when it comes to building a continuous cinematic universe brick by brick, and that impatience could be its ultimate undoing.

What do you think, dear readers? Let me know your opinions in the comments section below!