Been looking for this my self an app ideally tried neobackup and DataBackup on F-Droid on Android TV OS 12 no joy, it backs up something just the apk I think and some other useless part. But not the entirety of apps and games for both the apk and app data portion trying to restore fails as well with the apk launch, so I am stuck in this same boat my self.

You might want to try those on a phone if that's what you have it requires root though.

But I scoured the net in search of an app for a whole day as well but had no finds for doing a backup that worked for TV OS of any kind, so I'm not sure what to do short of finding a dev and begging them to generate a nandroid backup-able TWRP .img file and flashing it problem is flashing it likely wipes the lot before using it, and it needs to be a specific .img for this specific TV box and for specific other devices, this is just so I can backup the games and apps incase the HDD dies ever, as there is no longer a way to backup and restore them on higher than Android 9 I think it is?

What a joke though, it's becoming pointless on purpose. Probably to stop people going for none proprietary devices/products to play the games and apps with like the new bag of sh@t Google are releasing some TV box that mine makes look like dog sh@t any way and mine is 2yrs old already a Mekotronics R58.

This is a growing problem that hardware manufacturers of the boxes should be fixing with their own backup tool to backup per app apk+data and as a .img file style backup in one tool but they cannot be bothered, in fact many are making devices abandonware too quickly to care about letting people do the fundamental necessities the boxes and phones should have like backing up.

Here's a caption from this github page https://gist.github.com/AnatomicJC/e773dd55ae60ab0b2d6dd2351eb977c1

sadly I doubt that works on Android 12 due to limitations.

To help protect private app data, Android 12 changes the default behavior of the adb backup command. For apps that target Android 12 (API level 31) or higher, when a user runs the adb backup command, app data is excluded from any other system data that is exported from the device.

This does sound very promising though not tried yet?

https://www.xda-developers.com/swift-backup-android-12-shizuku/

UPDATE PROBLEM SOLVED

It works Swift Backup is working for Android TV OS 12 apps and data with root apparently it can work without root over adb using Shizuku, I have successfully restored Huntdown game with data on a secondary hard drive from an adooted storage hard drive based device, you can choose individual or batch app backup to internal and external also it allows media backup not sure whether it means videos and music only or everything else on internal storage or the media which is inside apps in some respect like some photo editing and video editing apps possibly?

Cons it is free up to 10x backing up of an app but does habe premium version to allow infinite backup

Ouch. Good luck with that 🤞