I love the custom FX engine, and have been playing with its parameters for a while - for a few effects I wish I had a little more control of a few features: spray/nozzle - the initial distribution of particles works fine for large effects, but for a smaller effect, they can end up scattered pretty wildly - a "nozzle" or "spray" parameter that would constrain or loosen the initial distribution of particles would help. accelerate/decelerate - kind of like gravity, but always pointed in the direction of a beam or targeted effect - it would automatically set the gravity towards (or opposite to) the direction of an angle -1 effect, or align the gravity of other effects to the angle specified. drift - an option to allow a particle to drift randomly in its momentum and acceleration after initial generation, adding to gravity and momentum. scale - an option to allow particles to change size after firing, growing or shrinking over time like the color and opacity. origin momentum - allow the focus of the effect to be animated as well, much like can be done with a mouse right now and duration -1