title: Box2d Collision not good enough
body: <p>in my game there are objects which falling from the sky<br>
  the objects collide with the hero (can move on x-axis)  </p>
  
  <p>the problem is that sometimes the objects kinda stuck/roll on the hero</p>
  
  <p>what I want is a big/major hit..
  which parameter of the fixtures/bodies I need to change in order to control the<br>
  force of the hit?  </p>