I couldn’t find a wishlist thread regarding replacement parts and accessories, so here it is. Maybe this could be helpful for the Clockwork team to figure out what we’d like to buy. Please join in and share what you’d like to see.
Here’s my list including things that might be unlikely:
You want clickier buttons? My favorite thing about the GS is that the buttons feel more like the Game Boy or SNES due to the elastomer construction. I think the directional pad could be improved though. But I might just design something myself to fix that.
I completely agree about the display but Im not really sure how they’d make a glass container. Maybe Just a different front piece that you can slide a piece of glass into or maybe one snaps into the center of a frame that has the right hinge on it. I’d even settle for a few piece of the same plastic and this time put a nice screen protector on it… 
How bout module upgrades that fit in the archetype shape but have either higher quality for each component, or along the same idea a lower power variant…etc
I wouldn’t mind an optional keypad with buttons like what the GameBoyAdvanceSP had (as that is the portable system I grew up on).
Wonderful, wonderful clicky buttons…
I’d quite like to be able to buy spare covers. I know the STL files are available but I imagine the quality is not likely to be so good. I found it difficult to choose just 1 front shell colour!
I would personally like to see them offer the lego back shell in multiple colors instead of just gray or black. I bought my Game Shell with the intent of doing a yellow front and a blue back, so it would be nice to have the lego case in blue and it would also be nice to have the light key module in different colors too.
+1 for glass cover of display container, or at least plastic with proper coating as screen.
The current display container not just too easy be scratched but also degrade the display quality.
My main problem with the buttons is that they sometimes get stuck in the Shell due to their travel distance and spunginess. In my case that’s mainly the B button (SNES Layout).
Aluminium Metal Case.
Hell yes! I’d love to see that. 
Make sure you trim all the excess from the molds. I had the same problem with buttons getting stuck, but when I trimmed them to be smooth they worked a lot better!
+1 to that, if you sand the excess of where the parts were joined to the mold they never get stuck.
Trust me, that’s what I did. Doesn’t solve the issue for me. The poblem seems to be tolerances in the cut-out of the front shell.
This could only be solved by a shorter travel distance of the button, and it being less wiggly.
I honestly doubt we will see a radical change in the keypad design for the time being, as it would need them to make new mold for the front and possibly back shell.
I unfortunately doubt this as well.
One thing I’d also like to have (and I might be the only one) is a little weight that fits in the free space underneath the speaker module. I’d love the Gameshell to be a little heftier.
You probably could do it yourself, but it would have an impact on the sound quality of the GS as this is used as a “bass boost”
I would like to see a set of female connectors to expand the Arduino, SPI and I2C functionality.
A hardware volume control and brightness knob would be great. Something that would work independently of the software.
It’s be cool if we could custom design a front/back shell and have them make it. I’d pay a good chunk for that. Not everyone has the ability to make their own.
In addition, I’d like a back shell with integrated shoulder buttons/light key. Right now the light key comes off too easily imo. Plus I think it currently doesn’t fit the streamlined design of the Gameshell.