boxtron VS luxtorpeda

It also allows you to install Boxtron, Luxtorpeda, and Roberta for some old school games, and then choose them in the launch options for Steam just as if they were Proton versions.

Boxtron is tool for automatically converting DOS games on Steam from using "old Windows version of DOSBox via Proton/Wine" to native Linux DOSBox - I specifically implemented there conversion of case sensitivity in .cue but also automatic rewriting of paths (because some game developers publish games on Steam without testing them at all). Right now it does not work unfortunately :( - when it'll be fixed I will post the update on this sub and /r/linux_gaming (and others as well probably).

Yeah, that's the annoyance of using flatpak unfortunately :( The version of Boxtron from flatpak store is designed to work with Steam installed via flatpak - which is not the case on SteamOS. I created a bug report for myself to fix it: https://github.com/dreamer/boxtron/issues/53 - you can follow the progress there.

Boxtron

I dont use this but have you tried taking a look at this wiki article: https://github.com/dreamer/boxtron/wiki/Configuration

For DOS games on Steam, there's also a Proton alternative called Boxtron that is basically DOSBox packaged to work as a Steam Play compatibility tool.

There is also OpenGothic. Which can be used standalone or through Luxtorpeda.

Detect zip automatically instead of metadata prompt, update to v2 json by @d10sfan in https://github.com/luxtorpeda-dev/luxtorpeda/pull/210

Bit late but luxtorpeda has gzdoom as an option along with qzdl for launching with mods. You just gotta install protonup-qt from the discover store in desktop mode. A quick YouTube/Google search can show you how but that's the rough gist of it.

I use ProtonUp-Qt to get different Proton versions. You can find it there. You could also manually install Lux. Then just select it from the Compatibility tools.

try using Luxtorpeda to install ECWolf to play it instead

Released a new luxtorpeda-dev client (https://github.com/luxtorpeda-dev/luxtorpeda/releases/tag/v63)

There's a project called Luxtorpeda which acts as a compatibility layer in Steam but instead of running the game through Proton, it will download and run it with native engines and source ports. So if you enable it with classic Doom it will pop up with a dialog asking which port to play with (GZDoom, doomsday etc) and it will count towards your Steam play time, enable the Steam overlay etc. Keeps the engine up to date and works with lots of other games with open source ports too.