i am so glad i could give a somewhat reasonable input! yeah two buttons on the lower corner of the screen (for righties, they can swipe anywhere on the screen with the right hand for the basic moves, and the two buttons are on the left corners to control gravity/new mechanic. switch that for lefties in the settings). the buttons can be diagonally positioned close to each other. one of them is the analogue stick to shift gravity in 4 directions and the other is based on your new mechanic. the player can swipe wherever for the basic moves. i think it would be really organic and ergonomic.
i honestly cannot wait for the full game!