In Andrew Cunningham’s piece for Ars Technica on new “mini SSDs” coming to the market (“Tiny, removable “mini SSD” could eventually be a big deal for gaming handhelds”), he justifies the need for these faster, higher-capacity drives by pointing to the growing size of game installs:

A 2023 analysis from TechSpot suggested that game size had increased at an average rate of roughly 6.3GB per year between 2012 and 2023—games that come in over 100GB aren't the norm, but they aren't hard to find. Some of that increase comes from improved graphics and the higher-resolution textures needed to make games look good on 4K monitors and TVs. But TechSpot also noted that the storage requirements for narrative-heavy, cinematic-heavy games like The Last of Us Part 1 were being driven just as much by audio files and support for multiple languages.

He follows up with a Mac example:

For another prominent recent example, consider the install sizes for the Mac version of Cyberpunk 2077. The version of the game on Steam, the Epic Games Store, and GOG runs about 92GB. However, the version available for download from Apple's App Store is a whopping 159GB, solely because it includes all of the game's voiceovers in all of the languages it supports. (This is because of App Store rules that require apps to have all possible files included when they're submitted for review.)

This difference in install size really seems to bother Cunningham. The link in the above paragraph is to Cunningham’s July piece on the release of the game for Mac, where he wrote:

The game will also require 92GB of storage when downloaded from Steam, GOG, or the Epic Games Store and 159GB of storage when downloaded from the Mac App Store. The difference in size is because the App Store version “has all voiceovers included” and because Apple’s App Review guidelines (see section 2.4.5, item iv) prohibit apps from downloading additional files after the initial download is done.

Alas, both parentheticals and his reasoning are wrong—stemming, I presume, from a misreading of the App Review Guidelines and an unawareness of available APIs for reducing app download sizes.

The guideline Cunningham references says:

2.4.5 Apps distributed via the Mac App Store have some additional requirements to keep in mind: […]

(iv) They may not download or install standalone apps, kexts, additional code, or resources to add functionality or significantly change the app from what we see during the review process.

This is a prohibition against changing the behavior of an app after it’s been reviewed and approved—think a vision testing app turning into an illegal streaming app, or a seemingly innocuous game transforming into an antitrust lawsuit.

What it’s not saying is that apps must “have all possible files included” in the downloaded app package. Downloading additional content is definitely allowed. Two examples from Apple itself:

• Logic Pro: a 6GB initial install, with optional instruments, effects, and samples taking up to 72GB.
• Xcode: a 12.5GB initial install, with optional SDKs, simulators, and tools taking up to 41GB.

Apple does require “all possible files” to be available during the review process, but that doesn’t mean those files must be included in a single app upload.

At WWDC22, Apple introduced Background Assets, with the express purpose of enabling smaller initial app and game downloads, allowing developers to carve out assets—say, voiceovers in various languages—so they can be downloaded (or not) as needed. If a player only wants English or Mandarin voiceovers, the app doesn’t need to include French, German, or Jamaican Patois in the download. This provides a smaller initial download (and on-disk footprint)—no bloat, no wasted storage space for never-to-be-used files. Of course, should the player want Jamaican Patois, it’s just a download away.

By implementing Background Assets, developers allow all their downloadable assets to be seen by App Review. Those assets are downloaded by the app during review as needed, just as they would be when in the hands of customers. Developers do not have to upload a single binary containing all the assets for Apple to review their app.

(If those assets aren’t available during review, the app gets rejected. This catches many developers who, for example, expected to enable their production servers only after approval, not realizing that those servers are used during the app review process.)

While it may be true that the complete Mac install of Cyberpunk 2077, with all the voiceovers, requires 159GB of storage, it absolutely does not require all 159GB to be part of one download package. That the game has such a large footprint is the developer’s doing, not the result of an Apple requirement.