There’s setting(s) in EmulationStation (in RetroPie) that can make it kid friendly.

…org.uk/…/Child-friendly-EmulationStation/

That said, batocera.org is a fork of RetroPie with a lot of sensible presets to make it quite a bit harder to break.

If you don’t mind jailbreaking, the Playstation Classic appears to be going for about $100.00, and I understand it can run Genesis and SNES emulator a as well once jailbroken.

Another great option to consider is the Evercade VS: theverge.com/…/evercade-vs-retro-console-review

And the HyperMegaTech Pocket - which does a terrible job advertising that - it plays the same cartridges as the Evercade VS. www.hypermegatech.com

Evercade has a simple interface, and is easy to factory reset: evercade.co.uk/support-vs/

Evercade has a good mix of recognized retro (and new retro-style Indie) games available from Taito, Data East, Atari, Epyx, Team 17, and some real hidden gems from Gaelco, Jaleco, MegaCat, Toaplan, IREM, Piko, etc.

Evercade carts are about $20+shipping, and come with anywhere from 1 (new Indie game) to 20 games (Atari 2600) on each cart. More typically around 7 games per cart. About 14 news carts were released last year, and there’s a bit more than 500 supported games so far. evercade.co.uk/cartridges/

Source: I’m a minor contributor to the RetroPie ecosystem and a huge Evercade fan.