The game runs fine.

systemd-inhibit game-performance %command%
Perfectly smooth without bugs
Game Runs at 60fps on highest settings out of box. Does consume 16-22 watts unrestrictied so you might want to set a TDP limit. Game can dip into 50s range when there's a lot on the screen. Steam sets a community made control layout when you first launch the game so I'd recommend chainging it to a Gamepad layout as the game has controller support.
Worked out of the box.
works out of the box
only played for 30 minutes
Works perfectly fine
Игра идет идеально

I think there are some frame timing issues because sometimes the game does not look "smooth" but overall, it is working properly.
PROTON_NO_ESYNC=1 gamemoderun mangohud %command%
Game works without any commands but if you see excessive CPU usage the esync command can make it run smooth as butter.
mangohud gamemoderun %command%
No outstanding issues have been noticed after coming back to this game and diving into some post-game content.
Right out of the box.
No lag, no fps drop, no stuttering, no input delay, no audio issues. 10/10 Recommended.
Played through over 50 missions and watched many cutscenes and plays flawlessly

6.16-GE-1 GloriousEggroll
GloriousEggroll Proton fork improves the performance by a significant amount.
There's a significant notice in performance between playing it natively on Windows and running it via Proton. It's not unplayable, but most people with higher spec machines will probably be able to run the game at a smooth 60fps or above.
It's definitely playable. The infinite loading screen issue is fixed, but it still has some performance issues that prevent it from being a truly native experience, but given how far Proton has come, I'm sure the issue of performance will be solved later down the road.
Works great since 6.3-5

Proton-6.10-GE-1 GloriousEggroll
Proton-6.10-GE-1
I sometimes get some small framerate dips in combat, but mostly runs smoothly

Proton-6.10-GE-1 GloriousEggroll
Proton Experimental or GloriousEggroll's latest release: https://github.com/GloriousEggroll/proton-ge-custom/releases
This game used to suffer from an infinite loading bug in Proton versions prior to 6.8. It is unknown as to what causes this problem, but using either Proton Experimental or GE-6.9 or later causes missions to (finally) load properly.
The game now appears to run more or less perfectly in gameplay, though I have not currently had much of a chance to test as throughly as I would like.
Besides Proton GE 6.9 or higher, the game also works with Proton Experimental out of box. Proton 6.3-4 has an infinite loading issue
Besides Proton GE 6.9 or higher, the game also works with Proton Experimental out of box. Proton 6.3-4 has an infinite loading issue
As per UrsaJasper's report the game is playable with the, as of typing this, current glorious eggroll proton (6.9_GE_2-2).
The game seems to run fine when in the mission - I haven't noticed any super large slowdowns as of yet.
When loading the missions the game will drop frames
Be sure to run the latest version of GE proton - I think that may be what has completely turned the game from unplayable (infinite loading screens) to completely playable. Missions and everything seem to load fine now, and I did not have to do any further customization other than the latest GE (5.9 as of writing this)

Hangs trying to start mission one with both 5.13-4 and Glorious Eggroll 5.21-GE-1
Not much else to add, really; it's the same problem everyone else has reported in previous versions or Proton. Disabling ESync does reduce frame hiccups significantly, however, and basically halves CPU usage.
I set up a logfile but I'm sure how useful it is; there is a repeating error while the game is starting where it can't find a rendering module for an overlay, but it seems doubtful that this would cause the infinite loading error people have been reporting.
However, there is also an unmarked error later on which might be more fruitful, as this reports creating a minidump:
Unable to read VR Path Registry from C:\users\steamuser\Local Settings\Application Data\openvr\openvrpaths.vrpath Setting breakpad minidump AppID = 899440 Steam_SetMinidumpSteamID: Caching Steam ID: 76561198005614259 [API loaded no]

Maybe just a fluke, but the game didn't originally go into the loading screen upon starting the first time I launched it without disabling Esync.
When looking around on the caravan I noticed that the framerate dips into the 40s. I'd imagine this problem would be even more severe in actual missions.
While everything else works, loading into missions is impossible. Upon readying up you're met with an infinite loading screen that never ends.

Proton-5.11-GE-2-MF GloriousEggroll
Sadly the game is not able to load a mission. It hang in an endless loading screen.

It starts, but the first mission does not load. Those. endless loading
The first mission does not load
Unfortunatelly, the game won't let you load into first mission

PROTON_NO_ESYNC=1 %command% fixes all my FPS issues and the game runs completely fine. But sadly when going on missions the game gets stuck in a never-ending loading screen. Real shame!

None of the below input problems. FPS is fine, but maybe that's just because of high enough specs.
All versions of proton currently have infinite load time. This game does not use Denuvo like the previous God Eater games, so that's not the problem.

Performance is noticeably improved over 4.2-9; dips are still present but the overall framerate is considerably better. Unfortunately, as with previous versions, it is still not possible to enter a mission due to an infinite loading screen.
Further, this version introduces a new bug: Steam managed controllers (or Switch Pro, at least) do not behave correctly. Random inputs are fed to the game (although curiously no inputs are received during the opening FMV at all) if the controller is plugged in when the game starts. If the controller is plugged in later (but Steam configuration is still reported as successfully loaded) the game will fail to receive inputs. As such, it is no longer possible to use a controller that is not natively supported.

As of this latest proton update, still stuck at an infinite loading screen.

Game loads fine and goes to character creation and from there to lobby but when you start the first mission the game does not go further than that. It just keeps loading. Disable Esync tweak gave a little boost to frame rate.


Infinite loading screen on first mission


One can walk around after character creation, but leaving for the first mission always leads to an infinite loading screen. Have tried modifying all graphics settings/ full screen settings.


Installed the game and it worked out of the box without any tweaks



crashes in the loading screen after character creation or in the loading screen of Load Game


The game crashes in the loading screen that occurs after you hit "New Game." The startup screen looked fine though, and the anime opening movie played.