The puzzles in Puzzle Agent 2 (PA2) weren't very good. Most of them were repeats of ones you already did in the first one, and there were several of the same type in PA2. Many of the puzzles were too simple as well; too simple or they were lame. I beat this game without using an online guide or anything (not sure what Ross meant when he said he almost beat PA1 with no hints, do the in-game hints count?).
All of the Japanese guy's were stupid puzzles that were either toying with the idea of a puzzle itself, not real patterns or requiring rote memorization of something you already had to know. I don't think it's cheating to look up the answer if you already know what it is but can't recall all the information, but these are just stupid "puzzles" and you might as well just use hints to figure out what it's getting at.
A few of the puzzles in the game have poor instructions that do not explain everything or there are gored sentences.
I guess one redeeming quality is that at the end of the game it let's you go through all the game's puzzles and a few extra they through in.
The game is massively skippable, unless you want some more Grickle story.