If you've ever heard of the book, SILLY MILLY, or played Silly Sally before, then you will be familar with this game. The worksheet follows the traditional game format but since it's subjective, there are multiple answers for each.
The general rule of Silly Sally is that Sally only likes things with double letters. For example, she like puppies, but not dogs. She likes pools, but not beaches.
You're students can do this with you explaining the rules or just letting them see if they see the pattern. This also allows them to have a new word game to play that boosts reading and spelling patterns :-)