I think I spotted your issue (in the ‘massage arrive’ section)… “ome” instead of “/home/” (and ‘user’ needs to be whatever your system is setup as). but make sure say GE 8-12 is selected at right click game shortcut ‘Configure > Runner options’ and on ‘Wine version’ make sure something like ‘lutris-GE-Proton8-12-x86_64’ is select BEFORE trying to run the game with that ‘Wine prefix’ stuff so it creates it completely fresh using GE 8-12 as this is what I currently am using on Lutris v0.5.13 for ‘Mafia II: Definitive Edition’ specifically.
but if you previously had saved game data from another location, you can transfer it to the new location if you need to otherwise you will have to start fresh. Mafia II: Definitive Edition save data location is (in your prefix location of course)… “Documents/My Games/Mafia II Definitive Edition/” ; the original 2010 game I have saves to another location, “AppData/Local/2K Games/Mafia II/”.
but with this Definitive Edition it does not require one install PhysX (for example… “PhysX-9.14.0702-SystemSoftware.msi” or the like) like the original 2010 version does (like if you try running the original 2010 version it flatout won’t startup until you install PhysX and this is regardless of whether you got a NVIDIA or AMD GPU, that’s a required installation), but I usually replay the original 2010 version since it’s less visual bugs and lower system requirements, so frame rate is noticeably higher on 2010 vs 2020 version. but you do have a NVIDIA 3060 Ti 8GB so I would assume your system will still more than comfortably handle the game as even my 1050 Ti 4GB handles it pretty well, just not as well as the 2010 version.
but when I start Mafia II: Definitive Edition for example I directly load it from Lutris using the ‘Mafia II Definitive Edition.exe’ file in the “/Mafia II - Definitive Edition/pc/” folder. but I do see ‘Mafia2Launcher’ folder in “Mafia II - Definitive Edition/pc/Mafia2Launcher/” and in there is ‘Launcher.exe’ etc. this might not matter much here though on which one you use, I just directly load the games main EXE is all.
just to make sure nothing is out of whack with the installation through Lutris, I would suggest running the GOG Mafia II DE installer through PlayOnLinux or say system installed Wine to whatever location you want to install it (say “/home/user/Games/Mafia2” etc) and after it’s done then simply make a shortcut to that ‘Mafia II Definitive Edition.exe’ file with the proper ‘Wine prefix’ like I was saying and see what happens.
but I also noticed Lutris has issues creating a ‘Wine prefix’ of more than 1 folder deep as if you go 2 folders deep it seems to act up, which is why I suggested to you to use “/home/user/MafiaII/” etc. because if you try, for example, “/home/user/RandomFolderNameHere/MafiaII/” I would expect it to have issues. but if you want to do that I found a work-around which is to just create the ‘RandomFolderNameHere’ in your file manager FIRST and then when you do “/home/user/RandomFolderNameHere/MafiaII/”, it should no longer have issues creating that basic stuff.
but as for your ‘sound’ issue… I am not sure, but I would imagine that ‘PulseAudio’ should be there which I would imagine should be okay by default on Ubuntu unless you did some random stuff in regards to sound as generally one should not have to mess around with sound stuff as it generally ‘just works’, at least it does on my Mint system.
but I would be curious to see what your Ubuntu says in regards to sound ‘inxi -A’ when running it from the live USB stick temporarily if it shows ‘PulseAudio’ or not like my Mint system does, which as I said in the past, is based on Ubuntu 22.04 LTS. because if it does and when you boot normally it’s not there, I would look into fixing that potentially.
but if you said the sound seems okay, you might be okay as-is, and no further action is needed here.