 
         tween.play()
 
-    lowerFields: () ->
+    checkEmptyLines: () ->
+        # count empty rows and columns and give extra points
         for x in [0..@board.size-1]
             isEmptyColumn = true
             for y in [0..@board.size-1]


            onFinish: =>
                if lastMove
                    @lowerFields()
                else
                    @moveToNextField(nextField)



        # threshold depends on current score, so more points you have -> longer path
        # you have to create to get moves bonus
        threshold = Math.floor(@level.score / (5*@board.size*@board.size)) + @board.size - 1
        if @moveLength >= threshold
            @level.movesDiff = @moveLength - threshold
            @level.moves += @level.movesDiff
