In game app updates, bypassing App Store
I see a lot of games do this and I believe it's OK.

Think of a game as being 2 pieces: the app (program) and the data it runs on. Apps are generally allowed to download and store data.

If an update is merely adding new zones or items represented as various files or tables (with no new programmatic functionality needed), then it only needs to request new static data.

However: game engine updates would require a change to the app and therefore an update via the App Store.