> Give the bullets gravity relative to each other. Now the particles can change direction very abruptly. It might be cool to have the red bullets stay as they

> Give the bullets gravity relative to each other. Now the particles can change direction very abruptly. It might be cool to have the red bullets stay as they are, but every so often have a larger, slow-moving "heavy" bullet that's a different colour and has gravity. And is maybe gently homing as well.