GameNetworkingSockets VS Proton

Steam does have a NAT traversal/punchthrough service too. It's apparently usable without Steam according to their README on https://github.com/ValveSoftware/GameNetworkingSockets but honestly the only easy to use implementation I know is in Facepunch.Steamworks which requires a SteamID to initialize

Halo was mostly all about single player and early multiplayer/local multiplayer but their online netcode has sucked since Blood Gulch. Lots of games do networking horribly, I have been in gamedev making networking and I hate most of what people do. The ones that have a clean natting, based on enet style reliable UDP channels, RakNet style punch are better (RakNet was good until Facebook bought it). It has come a long way but also fallen back. Valve source netcode (on github) is probably the best and you can check it out here. They started with the best in Quake networking, then to Source.

There are some general APIs that are tied to Steam, like some networking stuff (even then there's an open source library), but the devs are not required to use any of those. If the devs chose to develop exclusively for steam and use their libraries, then that's their own decision.

Keep in mind that if you do go the GodotSteam route, there's GameNetworkingSockets from valve that doesn't have the requirement of needing Steam that you can use for releasing on other platforms. It has the same interface as the Steamworks SDK without requiring the Steamworks SDK.

Their UDP-but-connection-based game networking protocol can be used completely separetely from Steam (it also supports encryption). I think that does not include their relay networking solution, but still.. maybe it's helpful. They also have a TCP-like interface to make it easy to plug into an existing solution.

You can also use the non-Steam parts of that library in any game in case you don't just release on Steam (have a look at https://github.com/ValveSoftware/GameNetworkingSockets )

If you want to go the route of using a raw protocol and packing your messages yourself, I suggest to at least have a look at Valve's GameNetworkingSockets either for inspiration of what you might need or even to just use the library: https://github.com/ValveSoftware/GameNetworkingSockets

There is early NAT piercing support in Valve's GameNetworkingSockets. Check out:

You can also try Valve's GameNetworkingSockets with a serialization of your choice.

Or Valve's Proton[0], a tool for playing Windows games on Linux.

https://github.com/ValveSoftware/Proton

Did you mount it with the correct flags?

there is a hack to try and use your existing windows game install from an NTFS drive, but i don't recommend it as steam will try to save file names that are not allowed on NTFS...plus ext4 is faster.

From a quick search, here's what I found. It looks like you're encountering some common issues that can occur with games running on Linux through Proton, especially with the recent updates to games like Satisfactory that might affect compatibility. The log entries you're seeing related to D3DCompile2 failing to compile shader and the issues with Ternary operator and LinearToSrgbBranching not being defined, suggest that there's a problem with shader compilation. This can often be related to the version of Proton or the graphics drivers you are using. Some users have reported that the game does launch with the -vulkan option but with graphical glitches and lower performance, which indicates that the Vulkan renderer is working but possibly not optimally on your setup. From the discussions in the community, users have suggested ensuring that the latest drivers for your graphics card are installed and, if using an Intel GPU, that the Mesa drivers are up to date since Intel XeSS references were found in the logs. If you're using NVIDIA graphics, make sure you have the latest drivers and possibly set the PROTON_ENABLE_NVAPI=1 %command% to enable DLSS if you're under Vulkan. If you're using an Optimus laptop with both Intel and NVIDIA GPUs, make sure your Optimus setup is correctly configured. Some users have found success by specifying DXVK_FILTER_DEVICE_NAMES=GeForce to force the game to use the NVIDIA GPU. It's also worth noting that if you're encountering issues with DirectX 11, you might want to try forcing the game to use DirectX 10 if possible or look into DXVK configurations that could resolve compatibility issues. Lastly, if none of these solutions work, you could try running a trace with apitrace to gather more detailed logs that might point to the specific issue. If you're still stuck, it would be a good idea to report the issue to the Proton GitHub page or seek further assistance in the game's community forums where others might have encountered and solved similar issues. For more information and to find others who might have resolved similar issues, check out the community discussions on GitHub​​, Steam Community​​, and the DXVK GitHub page​​.

This has been reported to the proton team here : https://github.com/ValveSoftware/Proton/issues/7317