Jurassic Park is an action game released on multiple systems to tie-in with the movie of the same name. In each version of the game the player takes on the role of Dr Alan Grant and follows the events of the movie (and the book it is based on).
There are numerous differences between the various versions. The titles on Nintendo's platforms were handled by Ocean Software while Sega's titles were developed by BlueSky Software.
The 1993 Sega CD version, which is an a point and click adventure game rather than an action game, has a separate page here.
BlueSky's Genesis title is a 2D platformer which allowed the player to play as either Dr. Grant or a Velociraptor while they attempted to escape Isla Nublar. Since the game began development before the film had been completed the designers had to borrow heavily from the novel for stages. With additions like the pump station and river levels being ripped directly from the novel.
Gameplay when selecting Dr. Grant is a standard side-scrolling action platformer. As he attempts to escape the island he amasses an arsenal of non-lethal weapons such as darts, smoke grenades, and tasers. This character's series of levels leads him through locales such as a power plant, a river (where he pilots a motorboat), and the interior of an active volcano. Grant's finale sees him reaching the visitor's center and escaping the island via helicopter.
Opting to play as the Velociraptor gives the player access to a completely different arsenal, namely the raptor's claws. The raptor's main goals are to eventually defeat Dr. Grant and reach the mainland. Playing through each level will require the raptor to defeat armed guards still stationed on the island as well as other hostile dinosaurs. The raptor's campaign is noticeably shorter than Grant's, completely skipping levels such as the volcano and river. Completing the game as the raptor shows that it successfully escaped the island by concealing itself in a crate that is loaded into a cargo ship.
After the successful sales of the Genesis version BlueSky released a sequel to Jurassic Park, Jurassic Park: Rampage Edition. The Master System and Game Gear versions of the game were similar to the Genesis version, but developed by Sega separately in Japan and didn't feature the raptor protagonist.
The SNES version of Jurassic Park is incredibly different from its Genesis counterpart. In the game the player controls Grant from a top down perspective and is given the task of collecting a number of velociraptor eggs before they hatch. Along with a much more cartoony and brighter look, it also has first-person indoor sections in the same vein as Doom where Grant has to collect key cards and codes for use outside.
For the most part, the game is very open-ended, not unlike some earlier Zelda games. The game requires Grant to do a lot of backtracking and hunting for items which helps progress the player through the story. Unfortunately the game has no save or password function so the player would have to collect all of the eggs in one sitting, a very daunting task with lots of trial-and-error gameplay involved.
Game Gear Version
The Game Gear version has more in common with the Genesis version, being a side-scrolling shooter. With the only weapon being a pistol, the player once again assumes the role of Dr. Grant. Progression from level to level is non-linear, giving the player the option to choose which area of the island they want to tackle first. Before the actual side-scrolling segments of each zone the player would play through a vehicle segment. In these segments the player would shoot down dinosaurs pursuing the jeep, successfully clearing these levels granted bonuses. Each level is unique in its design, showcasing a different area of the island, complete with a boss fight at the end. Clearing all the selectable levels opened the Visitor Center finale, where Grant would be confronted by the park's Tyrannosaurus.
Game Boy & NES Versions
Like the SNES Jurassic Park, the Game Boy and NES versions were also developed by Ocean Software. Also similar to the SNES version, the main goal of each stage is to simply collect a certain number of dinosaur eggs, opening access to the next area. Blocking progress through these stages is an assortment of dinosaurs, including main enemies like velociraptors, procompsognathus, and dilophosaurus. To deal with these threats, the player is given one primary weapon, bearing a strong resemblance to a rocket launcher. As Grant kills dinosaurs they drop ammunition for his armament. Interspersed between levels are boss encounters, including a sequence where the player is required to dodge stampeding triceratops, as well as a fight where Grant does battle with a Tyrannosaurus.