It’s through Proton, but the game runs flawlessly. Do note that you’re really going to want a controller for this one. Playing this with a keyboard is a miserable experience. Another thing is that there’s an unofficial tool for importing images over your custom graffiti, but it’s for Windows and I’ve never tried it with Wine.
The closest I can offer to what you’re asking for is that there are some e-readers that use Android. I own a Boox Page, which is one of those, and I’m happy with it. Boox products are a bit on the pricier side, but they do offer features that can be difficult to find on other manufacturers’ offerings, such as a micro SD slot.
Dreamcast ads got real weird. I vividly remember this one ad for Seaman: It showed a pair of feet and a fish tail sticking out from under a blanket. The accompanying text was "I will not mate outside my own species " repeated several times.
The Japanese version can be played in English if you have a MIL-CD compatible system. You’ll just need to burn a boot disc to a CD-R.
I’m happy with the 8bitdo controllers I’ve picked up. They’re great if you like the official controllers, but want something wireless.
I’m still salty about not getting an English release of Million Monkeys. On another note, Ape Escape Move was such a missed opportunity. Ape Escape’s gameplay was just asking for (preferably optional) motion controls, but instead they made a rail shooter.
Some old Archos media players, such as the 605 WiFi, run a locked down Linux according to Wikipedia.
This might not be as old as you’re looking for, but there was a really good homebrew painting program for DS called Colors. It even had pressure sensitivity on DS and DS Lite (but not DSi or 3DS consoles because their touch screens just didn’t have that feature).
I know you said no Pokémon, but what about Digimon? I think something in the Vital Bracelet family might fit your needs. It’s a watch with a character that transforms into more powerful forms based on your activity. There is a bit of an investment since you’ll need to buy the device itself and additional cards for more characters. Another thing to note is that all models except for the Vital Hero are (technically) in Japanese (there’s actually very little text because the menus are mostly icon-based). It also has a companion app called Vital Bracelet Arena, which can serve a storage for characters and allows for battling characters with other people (there no way for players to communicate with each other, so you don’t have to worry about your kid talking to strangers). If this sounds interesting, then I highly recommend checking out Humulos for more information.
Debian is always a safe choice for almost everything. It’s also worth checking DistroWatch. They have a search that can filter which distros are developed for a specific task (it’s under “distribution category”).
I have a T480 that I’m very happy with. With shipping I paid a little under $250. It came with 16GB of RAM and a 256GB SSD (which I replaced with a larger one).