While the movie differs significantly from the book, which primarily explored the scientific and moral implications of using genetics to resurrect extinct species-the dinosaurs representing the plot device of an out of control technology, the movie instead wisely focused more on the dinosaurs themselves. Clearly realizing that the visuals of Jurassic Park would be the dominating reason film-goers would want to see the film, much of the more "techy" aspects of the book were jettisoned. The book's lengthy discussions about the moral implications of whether companies have the right to patent living creatures created artificially were limited to a couple of scenes where Ian Malcolm (played with typical quirkiness by Jeff Goldblum) rebuked John Hammond (Richard Attenborough) for his lack of humility in utilizing genetic engineering to create the denizens of his park.
While I generally don't like to compare films or film technologies from different eras, I am going to make an exception with Jurassic Park, primarily because it was one of the biggest films to lead the charge towards CGI. Industrial Light and Magic had broken ground with some amazing CGI; first with the now almost-forgotten Young Sherlock Holmes, then their "fluid" creations in the Abyss and Terminator 2: Judgement Day, but Jurassic Park was likely the first to use fully rendered and textured CGI for a feature film. This was a major breakthrough, however the actual amount of CGI used in the film was limited to about four minutes-the remainder consisting of Stan Winston animatronics and in a few cases (such as the Velociraptor attacking Muldoon the gamekeeper) actors in suits. After twenty three years, and a deluge of CGI effects, some of the images have lost their luster, while others have stood up to the test of time. Having watched the film again recently, the initial shot of the T.rex snapping the fencing wires and striding between the Jeeps in the storm still has the power to suspend disbelief for this viewer. Obviously, the box office revenues for this film proved the merits of CGI, but considering that ILM had all but perfected computer aided stop-motion animation (their process labeled go-motion) it was a watershed moment when Spielberg made the decision to eschew go-motion for fully digital dinosaurs, and potentially a risky one. Since the visuals were originally conceived to be completed in go-motion, the switch to CGI required that the computer animators take months learning to realistically portray animals that veteran go-motion animator Phil Tippet had spent many years honing to near-perfection. Fortunately, Tippet was still kept on the crew which aided the transition from go-motion to CGI for the visual effects team.
Jurassic Park marks another transition of sorts, and a more personal one from Spielberg's perspective. Jurassic Park was one of the last films from the director that still echoed his earlier style of fast paced adventure, danger and inclusion of children to draw in juvenile audiences as well as adults. While the Color Purple was an exception from his usual reputation as a director of summer blockbusters, it was his other 1993 release Schindler's List that seems to be the dividing point between Spielberg the box office giant and Spielberg the artist. He still occasionally embraces the more imaginative aspects of movie-making, but Jurassic Park marked one of the last times he approached a fantasy/science fiction subject without a darker subtext lying beneath the story he was telling on screen.
Of course Jurassic Park was also enhanced by having John Williams compose one of his most memorable scores; the main theme becoming as familiar as Star Wars, and included in every one of Jurassic Park's sequels, including the recent Jurassic World. Williams's long time collaboration with Spielberg is probably one of the better examples of two diverse talents working together to create a product that is a visual and audio treat for the senses in a consistent fashion.
Overall, I think Jurassic Park is certainly a good film; having seen it in first release it had several "WOW" moments for me on the big screen (and as a die-hard fan of stop/go motion animation that means a LOT) My only real criticism is that because the CGI footage was sparse, the cuts between CGI and Winston's animatronics stood out to me even back in 1993, even though the matching up of the animatronics to the CGI was generally good. I won't critique the live actor's performances too in-depth; they were adequate for their time, and in particular Ariana Richard's character of Lex as a tween hacker was a relief over the book's portrayal of Lex as the whining obnoxious little sister of Tim. With the passing of twenty three years since the film's release it now has some dated aspects, not the least of which is due to what it inspired - a resurgence in dinosaur studies. What was state of the art knowledge in 1993 has become as outdated as the go-motion process due to new findings that continue to challenge scientific thinking about dinosaurs. Jurassic Park is still compelling entertainment and one of the most important footnotes in the history of movie visual effects.