Wow... I'd forgotten how much work went into prepping these!
This is my second packet of five pairs of challenging word puzzles. I say these are "ages 9+" because of the vocabulary level (POLITE, JUICE, FIBER, etc.), but make no mistake: these are challenging! I strongly recommend administering with an adult (or a designated helper) nearby to guide students with hints and nudges. I pilot test these on my adult friends as well as on kids, and more often than not: success is correlated with your critical thinking and patience more than your vocabulary or level of overall book-smarts.
I developed this suite of packets specifically for use after the year's tests are completed; we have several generic math and science themed worksheets but very few English activities.
If approached with teacher supervision: each puzzle is an opportunity to analyze and discuss metacognitive skills. Most of them emphasize nonlinear thinking; you can approach components in different orders, and through elimination you can slowly solve the most difficult problems.
After administering this a few times, I think the puzzle that stumps people the most in this set is:
Take the word CHIME. Remove one letter, and replace it with W, K, L, or N. What word do you get?