The Steam release of Lost Chapter, an NSFW roguelike deckbuilder, doesn't seem to work out-of-box on under Proton on Linux as of this writing (surprisingly, since Proton compatibility is very good these days, and a game not running is quite unusual for me).
I've seen some people on the Steam forums asking if anyone has a way to get it working. I took a look, and got it working, and wanted to post it on the Threadiverse so that search engines would index the solution it for anyone who's off trying to get it functioning.
The game is authored using RPGMaker MZ.
It looks like the Steam integration isn't functioning for some reason;
this causes it to fail at start. What I did was simply to disable
that, and then run it directly outside of Steam in Linux, using NW.js.
Apply this patch to disable the Steam integration:
unpack that tarball into the Lost Chapter game directory:
$ cd "Lost Chapter"
$ tar xzvf nwjs-v0.88.0-linux-x64.tar.gz --strip-components=1
And then just run the NW.js binary to launch the game:
$ ./nw
That's good-enough to just run the game directly from the command line and have it work.
The game doesn't -- as best I can tell -- appear to need to be run from within the Steam environment if invoked like this, but if you'd like to be able to launch it from Steam, you can do so as follows:
Go to Lost Chapter's properties in Steam. Then General->Launch Options. In that field, insert the following text:
echo %command%; ./nw
This convoluted "Launch Options" syntax is because Steam treats anything in this field as a series of environment variables unless the string "%command%" is present, in which case it treats the whole thing as a command line to execute. We don't actually want to use the original binary at all, in this case, but need to have it in the "Launch Options" text to specify the new binary name.
They don't have any existing solutions on ProtonDB, and I don't want to set up pseudonymous accounts on ProtonDB. This'll be enough for someone to find it with Google or Kagi or the like, and if someone wants to go do a ProtonDB entry, be my guest.
No. I did briefly try running it under vanilla WINE, and don't believe that it ran successfully. If it weren't able to run under a Linux-native NW.js, I might have spent more time looking at WINE compatibility routes, but at least from my standpoint, a Linux-native binary route was a preferable path.
If it is or becomes common for RPGMaker MZ games to be distributed with game-specific Windows DLLs or something, that might be something to look into.
Running it in Proton is so quick and easy, you might as well try it once. You've got nothing to lose. All you do is add non-steam game, then force it to use proton if you don't force proton on all games by default like I do.