3 colors would get interesting, because as the other two bully one into a corner, the small space causes rapid block zapping, quickly bringing it back from the brink of defeat.
That's definitely cool to watch, the patterns of territories get a lot more complex.
In that one balls seem to be able to punch through (and flip) squares (when going almost vertical) instead of bouncing on every square they hit.
It's a bug/choice that is present in the original as well.
Spent a fair bit of time watching that one last night, thanks. I can definitely see why computer scientists were entranced by Conway's Game of Life.
I was inspired by this and created a version with customizable ball count, accessible code... and a speed slider, to satisfy the less patient among us.