It's a concept, that in the video game development industry, sounds good on paper. But when it comes down to actually applying it to the game being developed, it can either be the best idea ever, a complete disaster, or completely avoided altogether in favor of the tried and true blueprint for success.
In the case of Resident Evil 3: Nemesis, they decided to pull the trigger on their attempt to reinvent the wheel, which ultimately would change the direction of the franchise forever.
The first two Resident Evil games followed certain styles, which was almost unique to the genre aptly named Survival Horror. They were slightly slower in pace, they focused on puzzle-solving and, obviously, surviving in methodical ways. Also, they were filled with quick, pop-up, "cheap" scares that were designed to work perfectly with the tension filled scare tactics that was fueled by suspense and fear of the unknown.
With this game, however, they introduce a new enemy called "Nemesis," who pretty much stalks you throughout the game. Sometimes he is just a lurking presence, other times he pushes you into rushing decisions and making you play careless, but either way, he is pushing the action of the game the entire way. It's subtle, but looking back on it tonight made me realize how the developers really are trying to eliminate the "survival horror" label - or at least change the definition of it.
The game also introduced a few new aspects of the series, which I had completely forgotten about. This was first game where you can craft ammunition, which was cool back then, and still feels necessary yet enjoyable. Also, you can run up stairs without having watch a boring, lengthy cut scene, which is fantastic in its own right. The 180 degree turn that we all know and love? Yup, that started here, as well.
It was a cool idea to have the first half of the game be a prequel to Resident Evil 2, while the second half happened after the events of that movie. I had honestly completely forgotten about it until I started playing.
So yeah, all these new ideas to improve on the game would eventually be the building blocks for the series going forward, even if it wasn't blatantly obvious when it was released. Did these changes and the inevitable evolution of the genre make the series better? I'll leave that one up for debate.