This is the newest of the puzzler world series on nintendo DS/3DS and have to say it is by far the most challenging. With puzzles ranging from wordsearches, Fitwords, Crosswords, and sudokus there really is a puzzle for everyone.
There are some new puzzles from the previous versions of this game, these I think are what make this version of the game that much more challenging. I've lways had trouble with crosswords, so tend to leave them till last or at last until I've got enough tokens to buy hints which would help me massively.
The hints vary on each puzzle, the smallest amount of tokens you can spend is five, the second is ten and the most you can spend is twenty. In all puzzles you can get the chance to check the entire puzzle so far completed for mistakes, which is kinda helpful, especially for me!
After you complete certain percentages of the game you get awards, or trophies, bronze, silver and gold trophies are awarded. Which is a good goal if you tend to lack concentration. Personally I find wordsearches the easiest way to earn tokens, they do gradually get more difficult but you don't really need to use hints to complete them.
The 3D in this game is not really worth it. You could get the non 3D version and not lose any of the gameplay. In the puzzle themselves there is no 3D, it's only in the titles, and at the end of each completed puzzle there is any 3D, so for the extra money, it's really not worth it at all.
There are also mini games after each puzzle, where you get a certain amount of time to complete a challenge. It's worth noting you don't get any tokens if you do not complete these challenges. These challenges can vary from hangman to basic adding up.
Overall I would reccomend this game if you like a challenge and are fed up of buying constant puzzle books that clutter up the house. The 3D not worth it, and some of the puzzles are particularly challenging, but will keep you busy for a good couple of hours (or until you get bored).