My first is in puzzle, but not in quiz; my second is in bubble, but not in fizz, my third is in snappy, but not in bite; my fourth is in sunny, but not in light. What am I? Too easy? You don't have to be a literary genius to work it out, but few readers or writers can resist word puzzles. They might seem like a waste of time, but writers have a good excuse for indulging.
Crosswords are great for waking up and/or extending your vocabulary. Codewords where you are given a couple of letters on a crossword-type grid and have to work out the rest to fill in all the words, stretch your knowledge of spelling and letter frequency and combinations. Trackwords, wordsearches, anagrams–they all increase language skills, such as familiarity with synonyms and antonyms; develop a sense of the rhythm of language; how to think laterally and how to use language in a more subtle way.
Word puzzles are far more fun than trying to cram grammar books, and if they have you reaching for a dictionary, that's no bad thing either. If you're like me, you can never simply look up one word, but find one leading to another. 
To really put your word skills to the test, don't stop at solving acrostics or filling in the blanks, try devising some of your own. It's far harder devising puzzles than solving them. 
Bearing that in mind, maybe you'll look more kindly on my simple effort above. The answer is, of course: play. You'll find another on the Exiles of Ondd Facebook page, and I'll post the answer there next week. I hope you have as much fun solving it as I did coming up with it.