Open game center, goto games tab, tap "find game center games."
Yes
The Iphone
Yes
if you have an iphone 3gs or later then you have it. other wise you dont have it.
you dont
You can't as it comes as part of the default package of the iPhone
If you delete the game it will ask if you want to keep or remove it from your game center.
While holding the HOME button on the LARGEST IPHONE in the game, press the HOME button on YOUR iPhone/device. Your game will minimize which is normal. Open the game again and the door will open. See related link for screenshots.
Why's it matter? Get a life and get off the Iphone bro....
Game Center comes with iOS 4. You do not need to download the app. You are also unable to delete it so enjoy it.
While holding the HOME button on the LARGEST IPHONE in the game, press the HOME button on YOUR iPhone/device. Your game will minimize which is normal. Open the game again and the door will open. See related link for screenshots.