omg, i'd buy it! day one! with more levels too??
i think the controls would be very suitable for mobile: maybe just swipes to move left and right and a button to shift gravity. heck even "up/down" swipes can change gravity upwards and downwards would technically work.
you have a very original idea right here, it'd be a shame not to bank on it and release it for more people to enjoy. best of luck!