(1) Get EmuDeck if you like playing old games on emulators. It’s free, and very worth it. It takes a little bit of setting up but it’s mostly automatic, and it sets up each ROM as a non-Steam entry on your Deck library.

(I have mine set up with RetroAchievements.org so that I can have achievements while I play SM64 and OoT. It’s very cool.)

(2) I recently picked up Tunic, and so far it seems like a pretty good before-bed kinda game. It’s like Zelda 1/LttP.

(3) Or if you want a good new platformer, I recommend Pizza Tower or Celeste. They’re both immaculate platformers with little to no penalty for failure. You can’t die in Pizza Tower (only lose points), and Celeste only sends you back to the beginning of the screen on death so you really only lose 10-30 seconds of progress. Both are very easy to learn, with a crazy high skill ceiling. Also, PT has insanely good music, and if you like old cartoons like Ren and Stimpy you’ll love the art. I can’t recommend that game enough.

Both these games are tied for my favorite 2D platformers, and both work on Deck out-of-the-box, no setup.