OneBigGame describes it as "combining elements of pattern recognition challenges with the natural tendency of humans to tap along with music and words." It appears to put pulsing dots on the screen, leaving the player to tap them in time with the music -- though not necessarily providing a clear cue when to tap. You can try to figure it out by watching early footage taken from the GameCity conference last year (via Pocket Gamer), after the break. That early footage looks nothing like the new screenshots (above), so there's still an element of mystery.
Proceeds from sales of WINtA will benefit Save the Children, Starlight Children's Foundation and other charities when the game is released later this year.