The genius mechanic is the "Stress Meter." The game monitors how often you hesitate, tap the wrong button, or take too long. A high stress level triggers harder puzzles. To lower stress, you must breathe—or play the "Relaxation" mini-game (a biofeedback-like bubble popper).
Look for BrainChallenge2_360x640_touch.jar on abandonware forums or your old phone's backup SD card. brain challenge 2 360x640 touchscreenjar