In the rule “Collecting Cells” after the text “If the contents of that Cell are Snowflake, set the Cell Target to be a Frozen Cell, and ” add the following text:

increase the Puzzler’s Score by 1, then add all plain Cells containing Snowflake that are adjacent to it to the collection list, then

and in the same rule, after the text “set all plain cells that are not in the collection list and are adjacent to it to be Frozen Cells” add the following text:

, increasing the Puzzler’s Score by 1 for every plain cell that became a Frozen Cell when performing this instance of this step