The player characters are Alan Grant (Player 1) and Technical Sergeant Michael Wolfskin, a soldier hired by InGen (Player 2). Sent by John Hammond to regain control of the park, their task is to stop Lewis Dodgson's men from capturing dinosaurs. There are a few missions and after every mission (except the last mission on easy or normal) the players have bonus missions. The dinos and Biosyn troops get stronger and harder to fight as they go.
Killing a dinosaur, except Velociraptors and the T. rex, will decrease the Stock Level, which shows many dinosaurs are left on the island. Once the Stock Level decreases to zero, the game ends. However, Stock Level can increase at any time, due to natural reproduction. Killing Raptors and the T. rex does not affect the Stock Level because they have been deemed too dangerous.
Weapons specialized on taking down Biosyn troops, raptors, and the T. rex.
- Rifle: Standard firearm. Has infinite rounds and has the least damage.
- Sub-Machine Gun: About as powerful as the rifle, but it has more than double the rate of fire which depletes ammo quickly. Players start each mission off with 200 rounds, and ammo pick-ups grant them 100 more rounds.
- Shotgun: Fires three projectiles, one straight forward, the other two travel 45 degree angles above and below the direction the gun is pointed. It's the strongest lethal weapon, which can kill some enemies in one shot. Most effective in close range. Players start each mission off with 20 rounds, ammo pick-ups increase their reserves by 20 rounds.
Weapons specialized on subduing dinosaurs when the situation calls for it.
- Taser: An electric weapon, which if charged, fires a powerful electric burst that could kill the weakest raptors in one shot. Has infinite ammunition. The only less-lethal weapon that could kill a Biosyn soldier.
- Tranquilizer Gun: Basically, the non-lethal version of the Sub-Machine gun, as it has a similar rate of fire, starts off with 200 rounds, and does similar (slightly more) damage per hit. Best used against smaller dinosaurs.
- Tranquilizer Bazooka: Fires a rocket containing a dinosaur stun gas which can damage players if they're caught in the explosion. Players start off the round with 20 bazookas, ammo pick-ups give them 20 more.
- Super Tranquilizer Bazooka: The strongest less-lethal weapon. Fires an even more powerful stun gas rocket. They can only get this weapon if they play the game on normal or hard difficulty.
- Biosyn trooper armed with a flamethrower (Blockade and Biosyn Headquarters)
- Biosyn helicopter (Protect the Gallimimus)
- Tyrannosaurus rex (T-Rex Scuffle) (final boss on normal mode)
- Biosyn helicopter (Escape) (final boss on hard mode only)
- Velociraptor: Fast, powerful, durable, and can often be found in groups. There are three types of raptors which vary in durability, brown being the weakest (it can be taken out by a single charged taser shot) and dark grey being the strongest (has about triple the HP of the brown raptors). They attack players by pouncing at them which knocks them down if they're hit.
- Tyrannosaurus rex: The most powerful dinosaur and boss for two of the levels. It's invincible the first time the player confronts it, all they can do is try to escape by slowing it down with their weapons. The second time they fight it (only available on harder difficulties), they trade their jeep for 20 super tranquilizer bazookas, which when combined with almost all of other weapons is just enough to take it down. It can attack players by biting or by stomping them, both of which deal very high amounts of damage.
- Triceratops: The second most powerful dinosaur, and only encountered in underground lava levels in very narrow rooms. It basically charges at the player and backs off a bit, then charges again.
- Dimorphodon: This flying reptile can be found in underground lava, flying everywhere. It can fly and usually attacks the player constantly.
- Dilophosaurus: Stationary dinos slightly smaller than the raptors that fire spit projectiles at the players.
- Gallimimus: Unlike all the other dinosaurs, these don't intentionally try to harm the players; rather they just so happen to be in their way while they're trying to run for their lives from Biosyn hunters.
- Pteranodon: Found on rocky levels with lot of cliffs and endless pits. They are often found by their nests, yet can also be found just hovering in random locations.
- Compsognathus: They attack players by dashing from one end of the screen to another when they're on the ground.
- Oviraptor: They attack players the same way as Compsognathus, except it's bigger, a lot rarer and can take more hits.
- Giant mosquito: They appear as enemies in many different levels. They fly around wildly and are purple in color.
- Tyrannosaurus rex
- Grenadiers: These men wear yellow jumpsuits and gray helmets with face masks. They stand in one place and throw grenades.
- Grunts: They come in two varieties, Caucasian and African-American. The Caucasian men have black hair and wear blue hoodies. The African-American men have shaved heads and wear teal shirts and tan pants. Both kinds of men run back and forth firing their machine guns or sometimes standing in one place, or dangle one-handed from vines and shoot.
- Flamethrower Troopers: These men wear gray jumpsuits and masked helmets and look similar to the grenade throwers. However, they wield flamethrowers. They walk forward, then stand in one place firing at the player.
- Engineers: These men hurl wrenches at the player. They're mainly seen in the Blockade level.
- Bazooka Troopers: Wearing black hats, purple shirts and green pants, these Biosyn troops wield bazookas. As the player approaches, they'll rush forward, kneel down and fire.
- Commandos: Wearing blue jumpsuits, hardhats and gloves, these men run forwards and stand and fire at the player.
- Scientists: These Biosyn scientists are balding older men in gray lab coats. They are equipped with handguns.
- Spy: An undercover agent in the InGen team's midst. He flees from the player and must be chased down and captured. He has a shaved head and wears sunglasses and a turtleneck sweater.
- Businessman: A Biosyn executive in their headquarters.
- Like many SNES games, bosses that aren't supposed to be robots/mechanical explode. In this case, the T. rex boss explodes when it is defeated.
- There are a couple cases of sprites being recycled for different characters:
- Wolfskin's sprite is essentially a recolor of Grant's sprite.
- The African-American Biosyn trooper's sprite is reused as the Jeep driver in the T-Rex Carnage level.
- The InGen scientist that the player must rescue at one point shares the same sprite as Biosyn scientists.
- Biosyn troops wear blue uniforms both in the intro and ingame. At one point in the intro video however their uniform becomes green.
- The tranquilizer bazookas can't harm Biosyn troops, but somehow can hurt players.
- In the game instructions booklet, Pteranodons are referred to as Pterodactyls in "The Missions" section.