Is it the portable, gadget-like functionality that you like, or is it that you want a functional portable Linux system that can handle emulators/retro gaming? If it's the former, maybe a project build based around a Raspberry Pi, like a PiGRRL
*? That gets you excellent hardware and software support in addition to good emulator performance, and it's still a proper Debian Linux system inside the case and can be used as such in a pinch.
If it's the latter, you're much better off just buying a used laptop and installing any Linux distribution you want, along with emulators and games.
Either way, you're getting more functionality for a fraction of the price**.
* Note that the "Add to Cart" parts list on the right side of that screen includes a 3D printer
, which is a little absurd given you could just have something printed at better quality from Shapeways
or a similar service, or by a local tool/CAD shop that will charge you a reasonable rate. Your public library might even have printers for use, it's becoming more common. AdaFruit is a good vendor if you do want to buy parts/materials from them, though, and their how-tos are excellent.
** Case in point - in May I picked up a Thinkpad T430 at an electronics flea market. From all appearances (literally no wear on the keys/trackpad, hardware visibly pristine) it had never even been used, just sat on a shelf for three years. Ivy Bridge Core i5, 8 GB RAM, 1 GB Nvidia graphics, 500 GB hard drive, $275. Still under warranty, even (checked on Lenovo's site before purchasing). Yes, it's three-year old hardware, but the performance is excellent, even better after I added an mSATA SSD. Not quite as portable as a handheld, but leagues better as a usable machine.
I guess if I want the GPD Win bad enough, I'll cut way back on soda and quit eating out. I guess I have to prepare myself for some major headaches.
Off-topic, but since you bring it up: if you get headaches when you don't consume caffeine, yeah, it's time to cut it out of your diet. I need to do the same every ten years or so - no caffeine for a solid month, to let my body adjust back to normal. It sucks
for a few weeks, headaches and grumpiness, but then I start to feel better. And the pluses are that I can start consuming caffeine again after I've gone through the process, and it takes far less to get the same perk as before I went dry.