I used two objects here to make the change clear. It can be the same shape, but the two object have a different animation. Perhaps the first has none animation and the second has.
Scene file: Sketch
Gravity can be added in Thinking Particles as well.
The Deflector was set to Event only, but it can behave like a surface where the objects bounce. I set it deliberately to zero speed (velocity) in the example, not a mandatory part.
Another option would be to have a longer PLA animation, and when it bounce (Event) it’s age get updated to the later state.
The interaction with other object could be done by attaching a Wind object to the position of the particles, so they can affect certain parts of the scene.
I will update the thread if I have some more ideas that are easy to set up, so far this morning I had no luck finding simple set ups like last nights exploration of it.
All the best