


Disgaea PC ran fine for me with the default settings. The only negative I really "had" were my game screenshots looking a little muddy; that's probably due to how old the game is though.
For reference: I played the game on Proton 9 and used the Gamepad controls.

Lowered TDP to 5
Changing to fullscreen in the settings does not work properly, creating an unworkable zoomed in layout. Luckily, the game defaults to a 16:9 window that works perfectly.
Needed community layout called "datbirds Disgaea Steam Deck Controls". Moving the track pad will allow the inputs to be ready.
PROTON_NO_D3D11=1 DRI_PRIME=1 %command%
Unless the given command line is given, and dedicated (AMD in my case) graphics forced, many textures (menus, character avatars) will be missing
With the default settings, the game will have noticeable bugs; Minor tinkering makes it work OK.
rm ./game.cfg && %command%
Crashes after first startup, you need to delete game.cfg to fix this.
Works great OOTB
One crash, but I think it was just a normal crash and not Proton-related
Something about the game suddenly spikes up the CPU/GPU usage. Because of that, the stats on the battery life isn't accurate and can be shorter. I recommend setting the TDP to 3-4 watts to avoid this issue.
In the game setting, set the Window Mode to FullScreen and FullScreen Mode to full. Otherwise the game window is cut-off or too small.
When I launched it months ago, it couldn't read the input from the controller. Touching the screen somehow made the input work. Now it is working fine.
Sometimes frame drops but it was due to flashy skills animation
This game runs really well on the deck.
Delete game.cfg before every startup.
Game will run initially with no hiccups. When you close and relaunch the game, however, the game will automatically close. Have to delete game.cfg and relaunch game everytime.
10/10 works perfect out of the box.
Major control issues (on all control layouts).
The game crashes if configured to use fullscreen
Manual fixing so that it is windowed is necessary for it to work properly.
Worked out of the box. I haven't jumped deep into it yet but right out of the gate it works perfectly fine. No issues so far.
Perfect anywhere
Out of the box
Out the box
Fantastic on low-end hardware

Game could not launch, workarounds in previous reports did not work.
I tried using Proton experimental, I tried using GE, I tried using the latest stable Proton version, none worked. I tried using launch options and workarounds from previous reports, none worked. I could not get the game to start at all, every time it would open a blank black window twice and then completely crash. Completely unplayable.
Disgaea runs great under Proton, no issues whatsoever.
-windowed
Fullscreen crashes the game
The game must be launched in windowed mode and (if using a tiling window manager) it has to be launched in floating mode, otherwise it will just crash on startup
The game window has fixed aspect ratio. When using tiling WM make sure to set the window to floating or the game will crash at start.
I'm using i3-gaps 4.20.1-2 and the issue was fixed by adding the following line to i3 config:
for_window [instance="steam_app_405900"] floating enable
Works great out of box on steam deck without any other proton versions. Use gamepad for optimal experience due to bug with mouse pointers
When using mouse input there is some weird de-syncing of the location of the mouse to what is on screen - but on deck the gamepad layout is native so this is a non-issue since you don't have to use a pointer.
Works great! Gamepad support is native and works just fine on steam deck. You have to set the deck resolution yourself once booting but runs like a dream beyond that.
Runs out of the box, with a slight cursor issue in fullscreen.
Slight mouse inaccuracy in fullscreen.
More or less perfect
Wrong resolution causes some mause inaccuracy
Alt-tabing might leave the screen black

create virtual desktop the same size as the main monitor
Works great, no issues
Works with Proton Experimental, I didn't need to tweak anything.

Proton-6.19-GE-2 GloriousEggroll
I installed vcrun2015 because Pretty Prinny need it
This game run poorly even on Windows

Game attempts to boot up and shows a black window before immediately crashing with a white flash.
Tested on Experimental, 6.3-7, 5.13-6 and 6.18-GE-2.
When having multiple displays, the game will limit resolution to the lowest one, even in fullscreen while being on another display (fixed with gamescope)
Tested on KDE X11 and KDE Wayland
KDE with Wayland makes the golden text boxes from the new UI disapear along with the characters name and sometimes the picture boxes. I fixed it by using GNOME Wayland.
Game would crash if left fullscreen after turning the game off and on again. As others have said delete game.cfg or make sure to make the game windowed before turning it off.
Controller would not work if it turned off while playing, to get it to work again I rebooted the game and it would work like normal.
Use of fullscreen required the deletion of /home/user/.var/app/com.valvesoftware.Steam/.local/share/Steam/steamapps/common/Disgaea PC/game.cfg before being able to reopen the game
Sony Duelshock 4 would not detect if plugged in before game was launched. Responded fine if plugged in once the NISA splash screen was up.
Save file would register last time played as GMT while system settings were in GMT-7
With the minor tweaks Disgaea PC plays identically to how it ran on Windows 7
Use of fullscreen required the deletion of /home/user/.var/app/com.valvesoftware.Steam/.local/share/Steam/steamapps/common/Disgaea PC/game.cfg before being able to reopen the game
Sony Duelshock 4 would not detect if plugged in before game was launched. Responded fine if plugged in once the NISA splash screen was up.
Game works fine, no issues with gameplay. Properly detects a gamepad. Might crash on startup but there's easy fix to that.
If game was turned off when being in fullscreen, next time game will crash on startup. To fix it, go to th game files and delete game.cfg file. After that game will work fine.
Crash on startup issue is easy to work around, doesn't impede gaming experience too severely.
Crashes on start with full screen enabled. Deleting game.cfg in the game directory allows it to start.
After purchase, tried starting game. Wouldn't start. Closed Steam completely, opened it back up, game worked perfectly after a second or two of starting up.