For example
birth_animation = animate(particle, time = 5, alpha = 255) // assuming they have 0 alpha on spawn
life_animation = animate(particle, time = 50, transform = matrix().Scale(2)
death_animation = animate(particle, time = 10, transform = matrix().Scale(4), alpha = 0)
Not sure how feasible this would be, but I figure integrating animate() with particles through their lifecycle would probably open up some reeeeeaaallly interesting effects.