next(options) {
		//go to the next level
		if (currentLevelIdx + 1 < levelIdx.length) {
			return this.load(levelIdx[currentLevelIdx + 1], options);
		} else {
			return false;
		}
	}
load the next level
@name next
@memberof level
@public
@param {object} [options] - additional optional parameters
@param {Container} [options.container=game.world] - container in which to load the specified level
@param {Function} [options.onLoaded=game.onLevelLoaded] - callback for when the level is fully loaded
@param {boolean} [options.flatten=game.mergeGroup] - if true, flatten all objects into the given container
@returns {boolean} true if the next level was successfully loaded