It's hard to believe that the original Ghostbusters was released 30 years ago.

That's why it was even harder to believe that Harold Ramis, who starred in the film, recently passed away at the age of 69. As a writer and director, Ramis created some of the most memorable comedies of the 1980s and 1990s -- including Caddyshack, the two Ghostbusters films, Groundhog Day, and Analyze This.

Ramis, who played Dr. Egon Spengler in the two Ghostbusters films, was originally set to make a cameo appearance alongside original Ghostbusters Dan Aykroyd and Bill Murray in the upcoming film Ghostbusters III. Sony (SONY -0.13%) has announced that the film's script will be tweaked following Ramis' death, but the project is still moving forward with Ivan Reitman, the director of the first two films, at the helm.

The original Ghostbusters: Ernie Hudson, Dan Aykroyd, Bill Murray, and Harold Ramis. (Source: Film.com)

The first two films, co-written by Ramis and Aykroyd, were both box office hits. The original grossed $292 million on a production budget of $30 million, while its sequel grossed $215 million on a budget of $37 million.

Despite that stunning return on investment, a third film never arrived.

The most commonly cited reason for the delay was the lack of interest from Bill Murray, who played wisecracking parapscyhologist Peter Venkman in the original films. Aykroyd, who played paranormal historian Ray Stantz, has been the most vocal about reviving the franchise -- throughout 2013, he discussed the plot of the next film, declared that shooting for Ghostbusters III will start in 2014, and openly criticized Sony for its lack of enthusiasm for the project.

Jonah Hill and Emma Stone were reportedly interested in starring in the new film, but Stone turned down the role last December. Meanwhile, not much is known about the film's plot beyond Aykroyd's claim on Larry King Now that the new script is based on research "in particle physics by the young men and women at Columbia University," which accidentally unleashes spirits from another dimension.

Ghostbusters III was already made ... as a video game?
Although the new film will be directed by Reitman and feature cameos from Murray and Aykroyd, it simply won't be the same experience as the previous films.

It doesn't star the three original Ghostbusters or fourth Ghostbuster Winston Zeddemore, who was played by Ernie Hudson. Hudson recently stated that there could never be a new film without Harold Ramis, whom he called the "glue" of the franchise.

Much of the charm of the original films comes from the incomparable comedic timing of the four main characters, the 1980s visual effects, and that unforgettable theme song from Ray Parker, Jr. -- things that would likely be lost in a modern sequel.

True Ghostbusters fans, however, will know that a "third film" was already made in 2009, with all four main actors -- Ramis, Aykroyd, Hudson, and even Murray -- reprising their original roles. However, the "film" was actually a video game (Ghostbusters: The Video Game) published by Sony and Atari, based on a modified version of Dan Aykroyd's original, unused script for Ghostbusters III.

Ramis and Aykroyd even rewrote the final script of the game so it would more closely resemble their original vision for a third feature film. Fellow cast members William Atherton (Walter Peck), Annie Potts (Janine Melnitz), and Max von Sydow (Vigo the Carpathian) also reprised their roles in the game.

Turning the clock back, digitally
The beautiful thing about Ghostbusters: The Video Game is that it turned the clock back to 1991, just two years after the events of the second film, allowing the aging cast to voice younger digital versions of themselves. The game also brought back film villains Gozer, the Stay Puft Marshmallow Man, and Vigo.

Ghostbusters: The Video Game is considered by many fans as the final chapter of the trilogy. (Source: Playstationlifestyle.net)

The game was fairly well received, with the Nintendo (NTDOY 3.03%) Wii version earning a 76% score on review aggregator site Metacritic. IGN called the game "a love letter to Ghostbuster fans," and Aykroyd said that the game was "essentially the third movie." The game -- which was released for the Nintendo Wii/DS, Sony PS2/PS3/PSP, Microsoft (NASDAQ: MSFT) Xbox 360, and Windows PCs -- has sold over 3 million copies worldwide.

For many fans of the original Ghostbusters, that game was a fitting end to the original franchise -- a final chapter that reunited the original cast in a digital format one last time. It would also sadly be one of Harold Ramis' two final creative projects, along with the film Year One, which he co-wrote and directed that same year.

The future of Ghostbusters
For many Ghostbusters fans, a new Ghostbusters film simply can't measure up to the originals without the original cast. Reitman and Aykroyd might be enthusiastic about moving ahead with a new film, but the death of Harold Ramis has made fans wonder if it's worth making at all.

Wouldn't we be better off remembering the 2009 game -- which was a true labor of love from the original cast and crew -- as the definitive end of the trilogy, rather than bring it back to ruin our fond memories of the fun films of the 1980s? Let me know your thoughts on the future of the Ghostbusters franchise in the comments section below!