How do we provide a prompt to download the game from the application?
The user doesn't cause a download to happen; you do, by asking for access to the resource. As for your app talking to the user, it's no different from putting up any other kind of prompt, if that's what you want to do: You can ask the user (using an alert or whatever interface you like) what to do, and if the user wants a resource, you request access to it.
Can we send a user setting to download over wifi only vs wifi and data?
No. The user can decide whether your app can use Cellular data.
What will happen if the user doesn't have enough storage on the device?
I don't know, but maybe if you are downloading from Apple, the App Store is able to negotiate this with your app because it knows the size of the resource to be downloaded.
Can the user clear games easily from their local storage?
No. The user has no access to what's going on behind the scenes. Neither does your app; you have no way of forcing a no-longer-needed resource to be deleted immediately. If you don't need a resource, you signal that by ceasing to ask for access to it. When the system needs the space, it will do the deleting.
If the app is forcibly closed during the download, will it again start downloading when the app is reopened?
Not by magic, no. But the case is no different from a resource that has been downloaded. It is always up to you to ask for access to a resource that you need, when you need it. It doesn’t matter whether the resource has been downloaded, partially downloaded, or not downloaded at all; what you do is always the same: you ask for access. If the resource you're asking for is present, you get access immediately. If not, then the download is performed in response to the request.
