Excellent game! I felt compelled to play Puzzle Books #1 and 2. I must say, your programming, interface, and puzzle design skills have improved a lot! I hope you'll consider updating the first two installments.
I especially liked that:
* You eliminated the Tab Cheat problem and made the key do something useful. I'd suggest looking into the tab order -- some of them are funky (hangman and sudoku, for example).
* You added the ability to skip levels. I have not been able to finish PB#1 & 2 and I'd like to see the remaining puzzles. And more importantly the solutions and logic to the ones I can't figure out. This is one of my favorite features of PB#3.
* The artwork is fabulous as in previous installments.
* There's still some guessing to the answers. Perhaps you could check for "other right answers"? For example, in Close Observation, I guessed what you were referring to but typed 3 other names for it. Then I figured I was missing something and spent a bunch of time looking for a different answer. It was frustrating to find that I was originally correct but didn't guess your name for the item!
I'm looking forward to future installments and I hope you let me skip levels in 1&2!