This is a very small complaint I would like to make about an otherwise pretty flawless game.
I solved all the puzzles in this game on the first try without using hints... or almost. There were two puzzles I didn't solve on my first try: "The Maw of Madness" and "Hydraulic Headache".
The reason I failed "Hydraulic Headache" was because I wasn't paying enough attention, but I would like to blame the fact that I failed "The Maw of Madness" on the developers. The problem is that the rules for that puzzle doesn't say that I have to fill all the yellow squares.
And there you have my minor suggestion for a puzzle correction. The only complaint I have about this game is that I would like to add the line "All yellow squares must be filled" to the rules section for "The Maw of Madness".
I don't want to be the sort of guy that only goes around complaining about stuff so I would like to end this post by saying that Puzzle Agent is a fantastic game and deserves as much praise that it can get. The people of Telltale games, you have done a great job, you're doing a great job and I see nothing but a great future for you.