Decent, fun games, but gets boring after a while. You'll use it a lot for the first few months, then get sick of it.
The different modes are pretty fun, but some of them are annoying. There is one mode where you use the touch screen to play piano, which is very annoying because you very easily miss the keys. Also, when you are playing games that involve numbers, sometimes you get the question wrong because it read your numbers wrong. So, the game has some flaws.
But, there are some fun parts to it too. As you progress through the game you unlock some more modes (some annoying and frustrating, some fun) and you learn some more hints about the game.
Overall, it is a decent game, but not one that you'll use every day. (which is its purpose.) After a while you'll probably only use it around once a week or less. If you already have Brain Age 1, than you should probably only buy it if you really liked it. (Or use it a lot) I can't compare it to Brain Age 1 because I don't have it.