You download one Big Fish app, and the games are all available within that app. Like what the Netflix app is for movies, the Big Fish app is for games. This is an interesting change in policy from Apple, to say the least.
[This was exactly the sea change I discussed elsewhere about apps being the new channel, or books.]
Source: Daring Fireball
[A follow up, that it looks like Apple allowed this by mistake and the app has since been pulled… We’ll see what happens next. But ultimately, apps as channels will happen IMHO.]