Growing up in the 90s, me and my siblings shared two original Nintendo Gameboys with a small selection of cartridges to play on them. My neighbour owned additional consoles: NES, SNES as well as a PC to play DOS games on and I was a frequent and fascinated visitor. I would be happy watch him play, sort of like an early Twitch experience before that existed.
Some 30 years later, we can now buy compact handheld devices that run Linux and dozens of emulators for all the 80s, 90s and early 2000s consoles and handhelds, with companies/brands like Anbernic, Miyoo, Powkiddy or Ayaneo releasing new devices every few weeks. Many of them as cheap as 50 $, shipping preloaded with thousands of games.
I have recently grown to enjoy to playing around with these devices, testing old games from my childhood and youth, fiddling with configs, emulators and custom firmware, and watching content of test reviews, game performances and hardware comparisons.
So why is it that this whole space/hobby has such an appeal to me and others?
For me it mostly comes down to:
There are soundtracks and specific sound effects in certain games that immediately transport me back to a time where I could spend the entire day glued to a screen, focused on defeating the next boss and reaching the next level, with close to no real life obligations except going to bed on time.
I haven't had a chance to experience many of the old systems/handhelds myself back then, be it consoles like the Playstation 1, Sega Mega Drive or early PCs like Amiga or Commodore 64. Each of these have great titles available that I never were able to take a look at. This is now very much a possibility: Browsing through romsets looking at preview graphics and then trying a title here and there is a lot of fun in itself.
Projects like PortMaster give you access to many old and new PC games on these retro handhelds: While compatibility differs vastly, it is thrilling to see one of your favorite games running perfectly on such a sleek little device and giving you the option to enjoy it casually on the couch, e.g. Stardew Valley.
Now, all of this would of course be possible on your smartphone, through emulators available e.g. on Android. And any budget smartphone can run circles around these rather weak devices, if you look at pure processing power. For some reason it makes a big difference though to have a more limited and focussed device that can only do this kind of stuff, while also having a retro vibe to it, and physical controls over touch controls. It also helps to not have battery anxiety while on the go, since you won't drain your phone by accident.
I have tried several devices (like the TrimUI Smart Pro and the RG35XXSP) so far that each usually have at least one custom firmware option that improves the overall experience (usually open source community projects), so I got to tinker a bit with with Onion OS, muOS, Knulli, Funkey-OS and Crossmix OS. Customizing game lists, scraping boxart, trying out different clamshell closing behavior (sleep, shutdown, resume last game etc.), honestly is just good fun as well. You can setup Syncthing to synchronize save states and emulator configuration between several devices.
With some devices you can modify the hardware, like taking it apart and installing a few layers of electrical tape to soften the clickiness sound and feel of the dpad and buttons if it's not to your liking. If you want better ergonomics, people are designing 3D-printable grips for many of the popular devices, or just spin up Fusion 360 and make one yourself!
I have seen videos of people replacing the rumble motor of a handheld with a small fan soldered in for additional cooling. This is such a cool space for people to explore and share tips and tweaks as well as reminisce in past memories.
Once I feel I won't use a handheld much any more, I pack it up and sell it or gift it to someone else, as I don't feel like building up a collection of them.
If you are curious about the entire topic, I recommend checking out this subreddit: https://www.reddit.com/r/SBCGaming/