The weird part of this post is I’ve spent a couple of days trying to get Disgaea 4 to work on my Deck and it really, really doesn’t. I know I’m not alone because the game’s forums have several threads of people complaining about it.
Slightly embarassingly, I also tested it on a Windows ARM device and it ran fine.
Look, compatibility on the Deck is… good for what it is, but it’s certainly nowhere near universal. Especially if you have a big library of games outside Steam, which I do. I’d still say it’s the easy go-to for a casual gamer mostly interested in older single player stuff or indie games, particularly for the price.
I mean, I pulled it from reality. I’m just assessing the way it works for the OP, not representing what you said.
As for Disgaea 4, I do believe that it works for you, the threads on the Steam forums also include people who say it runs for them, along with several who can get it to run by fiddling with Proton versions or doing some combination of launch options, multiple retries and settings changes. But it does have problems. It won’t run at all for me and others report frequent crashes, endless loading screens and other issues. It should definitely not have a Verified rating.
That’s the exception, not the rule, I just mentioned it because you pointed it out and it happens to be one of the games that don’t run universally for everybody.