I think whatever is required for third party apps and stores should also be required for play store. No special treatment for their own files.

Eg: “Warning: Are you sure you trust GooglePlayStore.apk? This software might be harmful.”

I reckon that Google would magically get the messaging exactly right with that requirement.

Nobody said you need to play a modern game. Just play an older or indie game and enjoy gloriousness.

https://en.wikipedia.org/wiki/Thorn_(letter)