In this case, would the components be combined into a list? Basically you’d have a BubbleComponent[] attached to the entity instead of just a BubbleComponent? Maybe I’m misunderstanding what the system is, is click_handler in the post a system, and if so, do systems only declare a single component of an entity as their input? From my experience, you often want to work with multiple components of the same entity in a system, for example:

-- Mark characters with 0 or less life as dead
function mark_dead(character: BoundaryComponent) {
    with character as movement: MovementComponent {
        character.x += movement.velocity.x * delta_secs;
        character.y += movement.velocity.y * delta_secs;
    }
}

Would there be a simpler way to query these components in the system, and what if I wanted to query for both BoundaryComponent and BubbleComponent, what would that look like?