Level constructor

Level(int initialTimeLimit, int initialScore, int targetScore, double laneSpeed, int level, int viewHeight, int viewWidth)

Creates a new Level

Implementation 

Level(this.initialTimeLimit, this.initialScore, this.targetScore, double laneSpeed, this.level, this.viewHeight,
    this.viewWidth) {
  this.timeLimit = this.initialTimeLimit.toDouble();
  this.laneSpeed = laneSpeed;

  this._dozer = new Dozer(this);
  this.visibleEntities.putIfAbsent(this._dozer.id, () => this._dozer);
}