A great tool for learning basic Japanese, but you're obviously going to need more if you're trying to become fluent.
There are a few games to choose from, but I usually play Flash Cards and Multiple choice for learning vocabulary words. I don't really find Whack-a-mole the best learning game for me, and the word search can be hard, especially when you've just barely been introduced to new words.
One complaint that I have about this game is the writing portion. While I think it was a great idea to use the touch screen to practice learning your Japanese characters, it has a few flaws. It seems to be either too lenient or too harsh on certain characters. Sometimes, I'll write something exactly how the game is doing it, and it will keep saying that I got it wrong. Other times, I'll draw a smiley face because I'll forget what a character looks like, and I will get it right.
One of my favorite things about this game is the dictionary. You can carry this around and pull it out if you need to know a certain word. There is also a section that has tons of basic sentences listed for you.
All in all, I think this is a very good tool to use for learning basic Japanese. You can always pull it out in your own time and do a few lessons. I am very glad that I got this game.