You can access this training program at any time. Select "Training" on the personal main menu. Scroll down to the bottom and click on the last "???". This will open the "Virus Buster" mini-game. It is basically "Dr. Mario," but with a mellowed out soundtrack and touch controls.

Brain Age 2: More Training in Minutes a Day Cheat: Choose Any Exercise

Select your player profile and head to the options screen (which contains Brain Age Check, Daily Training, et cetera). Hold down the select button and go to Brain Age Check. If you do it properly, you should be able to play any game offered in Brain Age Check. This cheat will therefore allow you to practice on all tests, furthering your skills. (unverified)

Brain Age 2: More Training in Minutes a Day Hint: Get Stamps

You can earn a Stamp everyday. You get a Stamp by completing any training game, and will get a new game to play after obtaining a new Stamp.