To losen up my shoulders in between NightFlight work, I toyed with some of the technologies I want to implement in future games. First of all 2D physics.
For that I chose Objective Chipmunk. It integrates nicely into cocos2D, and is insanely easy to use. On top of that, it is fast.
The mermaid demo below, simulates 400 snowflakes in a low gravity water environment. The idea was to make a fairly accurate simulation, and not just let the snowflakes magically enter at the top, and magically disappear at the bottom.
The mermaid is a small script file, with image data, and information on where the snowflakes can land, so making new scripts is very very easy.
Runs between 20 and 30 FPS on a plain vanilla 3G.