I try to ask for help, hoping not to be out of place and not to disturb in any way.
I installed Steam on Kubuntu 18.04 LTS (I was previously on Kubuntu 19.04). I can’t launch any video games I purchased, except Serius Sam Fusion 2017 (beta). In theory Doom 2016 should work but, by clicking on “start” the words “preparation for starting Doom” appear, after which nothing happens. The same happens with all other games.
Unfortunately, I’m not sure how to behave. I would like to launch the games in the linux terminal with Proton, so I can see the output, but I don’t know how.
I obviously wondered why no game started. My idea is that something important may be missing, but I don’t know what.
I installed the latest Nvidia 430 drivers via ppa. My system largely meets the minimum requirements; i have an intel 9700k and a 2080ti. Doom 2016, as well as Planet Coaster and other games I bought are graphically much more complex than Serious Sam Fusion 2017, so I thought they might lack libraries.
Unfortunately I am not very experienced with GNU / Linux systems, having read only a small part of the documentation of Debian-based systems, and having recently started studying something about programming.
I have always done other things with computers, but recently I decided to study, hoping to make some software in the future to give my contribution in some way.
Thank you all for your help.