public void createPowerup(Powerup pu) {
    for(int i = 0; i < powerups.length; i++) {
      try {
        if(powerups[i].living == false) {
          powerups[i] = pu;
          break;
        }
      }
      catch(NullPointerException e) {
        powerups[i] = pu;
        break;
      }
    }
  }