Physical buttons are meant for precise movement that is in core games. Something phones cant do. Phone games are shallow, copy and paste, unoriginal, and most importantly offer nothing more than 5 minutes of "ok this is a game" before you get bored because that is the entire game.
Two games that you could look at is Monument Valley and Infinity Blade which offer a little more at least. If I were to make a game though on mobiles, then id do a "recommended Gamepad controls"







