What are some things that you believe every idevice game should feature? Im going to start off by saying the obvious one; auto resume upon exit
The ability to play your own iPod music and flip the screen depending on whether you have an iPhone or iPod Touch.
Those 2 things. It amazes me that AAA titles are still missing the proper flip orientation for phones.
Good music, runs smoothly on -all- models (which most games fail to accomplish), rather complete and playable game upon release (eg, unlike Minigore), and -original and creative- gameplay/storyline (eg, unlike some crappy games that try to make quick cash by totally ripping off storylines, characters, graphics, music or even names from other games).
The iPhone and iPod have their headphone jacks at opposite ends. When holding the devices sideways, you will cover the jack and speaker unless you take into account which device it is and hold it a certain way. IPod = Home button to the right iPhone = Home button to the left Unless a game switches between all four orientations automatically (like Robocalypse), then it should support at least upright-vertical and the correct horizontal orientation depending on device. This is App dev 101. No excuses for getting this wrong at this stage.
There's something that I found in Ten squared, that would be amazing for games to include, but I'm not sure if it's in other games or which one it is in. Ten squared allows you to pause your game and access your library without closing the game itself. It's really neat and nifty and would love to see it in more games. It's not too much of a problem if games pause when you push the home screen button to change music and then resume where you left off, but it just kind of simplifies things, you know?