My toddler has a LeapFrog talking dictionary that drives my teenage daughter crazy. So I just started a project to replace its logic board with a RPi Pico 2 and interfacing with all ~45 of the toy's buttons and LEDs via a couple of GPIO expansion cards.

We'll have about ~300 short audio clips to record, and we'll store/access them via an SPI SD card reader peripheral. Audio output via a MAX98357A combo DAC/class D amplifier that we'll talk to via I2S. Powered by 2 AA batteries. Programming will be in CircuitPython, which is a cool way to teach the kids programming. (There are easy libraries for talking to all those peripherals.)