import megamu.shapetween.*;

Tween ani;
void setup(){
  ani = new Tween(this, 2.5);
}

void draw(){
  background(255);
  
  ellipse(ani.time()*width, ani.position()*height, 4, 4);
}

void mousePressed(){
  ani.setDuration( 30, Tween.FRAMES );
}

void mouseReleased(){
  ani.setDuration( 2.5, Tween.SECONDS );
}

duration

float: tween duration in seconds unless you've set durationType to FRAMES

durationType

boolean: Tween.SECONDS or Tween.FRAMES (smoother)