The zazz.march[] function is designed for very simple looping animations. It is tied to Decker's global frame counter, which makes it easy to use, but limits its flexibility.
If you have an animation that involves starting and stopping- or even starting and finishing- on a more detailed schedule, like a "cutscene", I'd recommend taking a look at Puppeteer. It defines a language for moving "puppets" around on the screen in various ways, playing sounds on cue, and quite a bit more.
The "ease" module offers another lower-level alternative, with functions for tweening a position along a spline defined by a series of control points.
Does any of that help?