This is based on the DIY Retro Audio Player: https://www.thingiverse.com/thing:5415382
It's a shrunken-down version without the display but works just the same. It uses the same PCB as the full-sized version. Be aware that this is not as polished as the fully-size Audio Player, so the on-off switch might not fit and the speaker must be mounted with hot glue.

Software: https://github.com/CoretechR/Retro-Audio-Mini

Inspired by 1980s tape recorders, this audio player was designed with ease of use and accessibility in mind. Despite its nostalgic appearance, it packs modern hardware. Powered by the ESP32, it plays music and audiobooks from a micro SD card, either on its internal speaker or though a headphone jack.