Here is my top finds in the Jurassic park Trespasser demo. It is first a description of the bug then a video showing it. It was found during a single week. The reason the clips aren´t longer than 30 second is that I did not have a full copy of fraps at the time.
Jurassic park Trespasser demo is found here

Title:
Skip the puzzle
Description of bug:
By going an alternative route You can skip the last puzzle
How to reproduce the bug:
Before the gate climb to the left and keep going as much left as You can and You will pass the most challancing part of the demo
Video of the bug:


Title:
Stuck to a barrel
Description of bug:
The barrel gets stuck to the player and can´t get off
How to reproduce the bug:
When picking up, throwing and dropping the barrels and other physical objects there is a small risk it will get stuck to the player
Video of the bug:


Title:
Transparancy glitch
Description of bug:
The player is able to see things that are behind bigger things
How to reproduce the bug:
look at the end gate and strafe around it and soon You will see it, look at video.
Video of the bug:


Title:
Trailer rolling in wrong direction
Description of bug:
If the player shots to high up on the trailer it will fall back instead of towards the player making it impossible to get down without dying
How to reproduce the bug:
Shot on the top half of the trailer
Video of the bug:

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