Hardcore gamers often dismiss the iPad and iPhone platforms as being for "casual players only" or not having the depth of traditional console games. However, it's becoming more and more relevant as a gaming platform due to the sheer volume and popularity of titles available--along with the technical capabilities of the platform.
One technical capability the iDevice family does not have, however, is a joystick (or joysticks.) You're left with only a capacitive touchscreen, which, though usable, can often be pretty miserable for gaming. Especially for those of short fingers, like yours truly--effective dual stick gaming on a touchscreen usually ends up being a painful. achy affair.