WackyToaster - thanks - it'll be a little while yet as I trawl through the normal physics actions etc. I'm currently creating all of the joint methods and some of the LFJS library is lacking, so my cpp skills are now above zero...!
mekonbekon - Thanks! That video is a good demo of how to get a water effect with a normal physics library. With LFJS, 1,000s of particles easily support 60 fps, so smaller circle sizes are easily possible. And, of course, the same Alpha Clamp effect can be used if you want. With LFJS you can also change the particle type: for example: water, spring, viscous, elastic, powder, etc. Each of those have unique characteristics within the engine.
Here's an example of the LFJS icon demo but using Tensile particles (mimics surface tension):