Cloud gaming services are not welcome on tvOS and iOS, Apple has confirmed in a statement to Business Insider. This will affect Microsoft's upcoming launch of 'xCloud' in September.
The battle over cloud gaming
A new wave of services, sometimes referred to as "Netflix for games", is coming. A cloud gaming service lets the user stream a game over the internet, like a movie for Netflix. Sony has operated PlayStation Now for several years and Google launched Stadia in raw form last year. Microsoft will launch 'xCloud' in September.
Such game services are not welcome on tvOS for Apple TV and iOS for iPhone and iPad at this time because games cannot be reviewed individually, according to Apple.
- "Our customers enjoy great apps and games from millions of developers, and gaming services can absolutely launch on the App Store as long as they follow the same set of guidelines applicable to all developers, including submitting games individually for review, and appearing in charts and search. In addition to the App Store, developers can choose to reach all iPhone and iPad users over the web through Safari and other browsers on the App Store," said Apple.
Apple is obviously not reviewing every new episode of a TV series on Netflix. The difference is that Apple is classifying games as apps.

Microsoft is planning to launch game streaming in September
Microsoft: No path forward
Microsoft is disappointed by the decision, which means that its new 'xCloud' platform planned for September 2020 cannot be offered on Apple's platforms. Microsoft points out that games are already being rated by independent industry ratings bodies.
- "Unfortunately, we do not have a path to bring our vision of cloud gaming with Xbox Game Pass Ultimate to gamers on iOS via the Apple App Store. Apple stands alone as the only general purpose platform to deny consumers from cloud gaming and game subscription services like Xbox Game Pass. And it consistently treats gaming apps differently, applying more lenient rules to non-gaming apps even when they include interactive content. All games available in the Xbox Game Pass catalog are rated for content by independent industry ratings bodies such as the ESRB and regional equivalents. We are committed to finding a path to bring cloud gaming with Xbox Game Pass Ultimate to the iOS platform. We believe that the customer should be at the heart of the gaming experience and gamers tell us they want to play, connect and share anywhere, no matter where they are. We agree," Microsoft said in a statement to The Verge.
Services like Steam Link where games can be streamed to Apple TV, iPad and iPhone from a PC on the home network are on the other available on the app store. These are allowed as they are classified as remote desktop solutions.
Apple operates its own game subscription service on iOS and tvOS with Arcade, which was launched in the fall of 2019. With Arcade, users download and install games rather than streaming them.
- Source: Business Insider, The Verge