I am currently working on something like this for audio, basically just like a MP3 player with full size SD cards that plays automatically when you insert them (for kids). It's actually quite hard to find full size SD cards these days and when you do they are comparatively expensive (opposed to current micro SD cards).
Also I wanted to have low capacity like 128MB, so the concept "one album, one card" (as in the OP - "one game, one card") makes sense. These are even harder to get and more expensive (in terms of money per storage). Naively I thought that obsolete hardware should be cheap.
It's probabably more sensible to have a drive for your full music collection and then use an NFC reader + cards to trigger an album. I see you can get 100 NFC cards for $22 on amazon right now. I saw some German blogs about doing this a few years back.
You are right that this is probably the more reasonable thing to do. I was just thinking that 1) I want to use full-size cards for better haptic and 2) have the actual data stored on the media. For instance when you are in the car with your playback box and the SD card you can listen without a network connection. But I concede that I am stubborn and this will probably be a dead end :)
You still don't need a network connection. Put a drive or SD card with all of your music in the player itself. You could put several hundred CDs worth of music in FLAC on a device for like $20, or up to like 4,000 CDs with a 2TB card (or 16,000 with an 8 TB drive), so probably more than anyone could reasonably own (or manage for a physical collection). Pennies of amortized storage cost per album even if you have multiple devices. It's nothing next to the cost of legally acquiring the music.
I remember seeing a blog post about this exact thing using nice little square NFC cards with the album covers on them. For anybody interested: https://hicks.design/journal/moo-card-player
I did something like this a while ago. What I did is upon reading the NFC tag with a raspberry pi, I'd call the spotify API to play an album in my google home.
This is something I want to see in the world. Do you have a public repo? I'm currently doing third party application development for the Yoto, and I've done a lot of hacking on MP3s. If you're open source I'd be interested in helping, or at the very least chatting about the project.
Eventually I will write a blog post. The software is actually not much, just some basic Arduino stuff. I am using an ESP32, a full size SD card board and a VS1053 board (both connected via SPI). The software is currently just trying to read from the SD card in a loop and when it can it just plays the MP3 files in order. Other things that are not connected to software is a Li-Ion battery, charger circuit, step-up converter, LM386 based amplifier circuit and a speaker :)
Super interested in something like this. Currently there is no easily operated audiobook player for elderly or people with severe arthritis.
My eventual workaround was cheap bluetooth speaker (because expensive ones did not remember playback position inside a track) and a whole heap of super low capacity usb drives.
My wife bought this. I was deeply sceptical. But it's lovely, you can put story cards in it. My 6 year old daughter loves it. And we listen to a daily yoto podcast at dinner every day.
Neat. I wonder if the files are stored on that card (and if yes, how) or if it works like the Toniebox where you have some kind of token that triggers a network download.
EDIT: this Reddit thread says it downloads the files. "All the audio files live in the cloud and it gets downloaded to your Yoto when you insert a card in the speaker. This means that you will need WiFi the first time you listen to a card, but should be fine without the next time you want to play the same."
Also I wanted to have low capacity like 128MB, so the concept "one album, one card" (as in the OP - "one game, one card") makes sense. These are even harder to get and more expensive (in terms of money per storage). Naively I thought that obsolete hardware should be cheap.