Gamestream can play anything. If you get a black screen when trying to play a game, typically its because it running in OpenGL i think? Basically if you change the video settings, or use Windowed Mode I think the video works. I used to play all my emulators off it, then I got a Shield TV and I can just play games on the emulators on it. It runs pretty much everything. I've played Dolphin Dreamcast off of Gamestream. If your game isnt picking up the controller, you can use Xpadder and make a profile that detects the controller and assign it's buttons to keyboard strokes. That should fix that issue.
As far as what I'm doing, is I'm making my own platform so I can basically "Link" the games I want to stream to it. Just to make it easier to organize and find my games from my Shield TV.
So my steps are:
Create the gamestream platform.
Change the platform for all the PC games from Windows to nVidia Gamestream so it shows a smaller library of games that I ONLY want to stream via Gamestream to my Shield TV.
Run Bigbox mode from Shield TV and I can easily navigate to that section to play games.
I can now update it to include the games I want easier.
The only problem I'm running into, is just adding one video game. It seems that LaunchBox can only import via Steam, GOG, etc, or Windows installs. So if I have portable games, they will not be able to be imported. Unless I don't know how to do it or haven't figured it out yet, it would be nice to have a "Add game by .exe" function and then have you input a string for it to search the GameDB to match the information to.
I hope this makes sense.