Jurassic Park: Trespasser invented physics engines in fps games as we know it. The game itself was a buggy mess and a financial disaster. The player's health was shown on the main character's boob for some damn reason. However, they did have the basics of a very good physics engine, and Valve took a lot of their ideas and incorporated it into Half Life 2.
Man, Trespasser is an example of a game with some pretty wild ideas about immersion and puzzle solving in a first person shooter game that the tech just wasn't quite able to pull off. If anyone is curious there is a positively antique Let's Play on YouTube that discusses the game's development, its relation to the wider Jurassic Park franchise, cut content, and, of course, the game in context. I think it may have come from the old Something Awful forums, and it remains, to my mind, the gold standard for what I'd like Let's Plays to be. Worth checking out if you've the time.