I had this RS-1 Plus handheld gaming console. I liked it because:

• comes with lots of games
• cheap I think about $15
• fairly comfortable and has actual buttons not like trying to play a game on a phone
• fun to play for a little while but not toooo fun that it can't be put down

main problem was it wouldn't save any progress even when the game seemed to allow it. I guess it just doesn't have any writable storage or however they got the games didn't include that function.

is there something similarly low end and simple that allows saving? I don't want to DIY.

See this weirdly sarcastic blog post about the RS devices for some info hal of which I don't understand.