How Do You Close An Apple Arcade Game On iPhone That Won't Close by Swiping Up? I'll answer it myself...

The answers given here to the same question were not helpful at all: Can’t exit Apple Arcade Games/Apps - Apple Community That should be fixed.

One correct answer is:

1. Ask Siri to open another app. Any other app.
2. Slowly swipe up on the app you just opened until you see all the currently open apps, which will include the Arcade Game you want to close.
3. You'll then be able to close out of the Arcade Game that is open by swiping up on it as usual. Done! That way you don't have to hard boot your phone to close the game app that is open!

This is a malfunction of the Apple software that should be fixed! You should in fact be able to close out the game by simply swiping up on it, but it doesn't always work. ;)