I've heard some complaints that even a free or $1 game should be playable offline. Me... I'm guessing that's too much to make demands [shrug]
WordWhile, my fill-in-the-blank game based on classic books, is only $1 and IS playable offline. For that matter, it has no ads or IAP and new playable texts are coming every 4-6 weeks as free updates for the next year as I build on the initial release. So, in short, I don't think it's too much to expect at all