Apparently it can be fun to train your brain.

User Rating: 8 | Brain Age: Train Your Brain in Minutes a Day! DS
Not really a game, but I still have some fun while playing this "thing"
Graphics aren't really there except for the big brainic on the other screen
giving all the explanations and questions.
This whole thing is text based and in all fairness pretty fun.
Don't know if it really TRAINS your brain, but none matter what
you'll have some fun time especially when you have to draw
some objects that they want you to draw.
I was surprised that it plays pretty good.... though I need to learn
to write perfectly while doing some simple math problems in high speed.