In the Jungle Road level, there is a Colt M1911A1 suspended high in the air, outside the bounds of the game. This gun is not used elsewhere in the game, although it was visible in pre-release screenshots.

It has no firing sound, has an unusually large ammo capacity, and does a large amount of damage. The flash uses a strange palette, and it is held sideways.

Within The Lab's basement is a hidden Quake logo. It can be used as a very powerful melee weapon and can kill a T-Rex in a just a few hits.

The dinosaurs were intended to have a complex AI controlled by an emotion system. However, the dinosaurs had rapid mood swings, sometimes switching behaviors so quickly that they just stood in one place and twitched. Not having time to fix the system, the developers worked around it by disabling most of the behaviors and increasing their anger and hunger levels.

In the Industrial Jungle level, there are a few raptors that the developers missed. One of them will walk around, but won't attack the player. Two more appear later in the level that will follow the player and sniff her, but will attack her if they are attacked or hurt themselves.

There is an unused melee weapon in an early prototype version of the game called the Dinosaur Tooth. The weapon was still mentioned in the game's official strategy guide despite being removed.

There is an area known as "Cathy's Beach" on Isla Sorna, where a condensed voiceover of Cathy talking to the Compy will play, as well as some creepy music.
The beach appears to be smaller than the one shown in the films, but the beach chairs and small tables are still present. This is a reference to the beginning of Jurassic Park: The Lost World where Cathy is attacked by Compsognathus'.

In Episode 172 of the webseries "The Angry Video Game Nerd" in which the Nerd reviewed Jurassic Park: Trespasser, James Rolfe conducted an interview with the game's executive producer Seamus Blackley about the game's development. He asked him why they used the heart tattoo on Anne's chest as a health bar, and shouting out the usage of ammo, rather than using a regular heads-up display. He responded:

"The idea was that you would feel that it was your adventure, and part of that was not having a bunch of technology in your face. And we were struggling with the idea of a totally natural interface, having everything in the game literally be in the game world in the context of the game world. The tattoo was one of the first ideas we had about a health meter, we were thinking of putting it on the arm and it happened to be on a tattoo on the chest when we ran out of time, and so that's what stuck and that's just how stupid things are."

In Episode 172 of the webseries "The Angry Video Game Nerd" in which the Nerd reviewed Jurassic Park: Trespasser, James Rolfe conducted an interview with the game's executive producer Seamus Blackley about the game's development. He asked him why they used the Tribe C Alpha Velociraptor as the final boss when raptors were already the most frequently-encountered dinosaur in the game. He responded:

"We didn't have time to create, or budget to create a new boss dinosaur, and we were in a huge rush to finish, and we had a huge amount of pressure from Dreamworks Interactive. Of course all of these things are ludicrous now when you think about them, because as we say 'a late game is only late until it ships, but a bad game is bad forever'."