Beyond that, there's a very limited range of games smartphones can support. Because of the lack of dedicated physical buttons, most action game just do not work

Beyond that, there's a very limited range of games smartphones can support. Because of the lack of dedicated physical buttons, most action game just do not work. The action games that do well are runners, because they remove nearly all the controls except for dodge. Because the screen is a touch screen you inherently cover the screen as you control the game. It's the reason the DS has two screens, so you can cover up part of the second screen without blocking the main action above.