itch.io

yes, understand that. Just was wondering if not using MP3 but samples via the Ultimate Audio Layer would be feasible instead.

If yes, it would greatly enhance the number of machines this can run on.

Just wondering, would this high quality speech and sound also be possible with the Ultimate Audio layer of the Ultimate devices? So the Ultimate 64, Ultimate II+ cartridge and the upcoming Commodore Ultimate?

See

https://github.com/GideonZ/1541ultimate/blob/e2186a7a04fdc2f38dd79ab631b3ed2b4dbfe701/doc/ultimate_audio_v0.2.pdf

and 

https://csdb.dk/release/?id=131522 ( which includes source code )