The "adjustment" you speak of is one that the developer needs to make during development of the game/app. When you browse the App Store, look at the "Buy" button and you'll see a small "+" sign in the upper left corner of some of the buttons. That will let you know that the app was made to take full advantage of the larger screen of the iPad family of devices. The absence of the plus sign signifies that the app/game is best viewed on an iPhone/iPod. Also, take a look at the app description, most of the time it will state whether or not the app was optimized for iPhone 5.