So over last weekend I was finally able to integrate the Box2D physics library into the Flixel framework. This isn't the first time it's been done, but I've only seen a handful of Flixel games that utilize it, so finally getting it to work is really exciting. If you aren't familiar with Box2D, it provides a very fast and very functional system for handling some pretty crazy physics, including collision, ray casting and force.
The value of Box2D I feel, in a Flash game, is incredibly high. The games I always end up playing again are the ones with interesting physics, but they also seem to generally be the most popular. I do think that the concept of controlling such a realistic and dynamic scenario is appealing for people, maybe because it resembles real life physics. Who wouldn't spend hours smashing buildings and throwing cars around?
I'm far from any real application to the engine, but like any game developer knows, the most important part is designing the core gameplay mechanics, which I now have. Here's a link to a small test I came up with:
http://www.newgrounds.com/dump/item/e6 da7295ac59cb8430aff53c9bcb80f0
You can hold down the mouse to create a gravitational field around it, and you can press the space bar to toggle gravity. Hope you enjoy!