Did you see the new checkbox for "overlay"
It is found below the fit to time. This showed up in release 3.3.0.
Try it on
fireworks, garland, circles, life, meteors, spirals, Spirograph.
i like the fireworks and Spirograph effects with overlay checked.
thanks don!
here is a 2 minute video describing how it works. video also suggests settings for fireworks and Spirograph.
https://vimeo.com/84090378sean