

If you like this kind of game and have enough patience to set the controls up, it's worth it.
Conflicting buttons changed for a smoother ride
Small in-game screens are not completely readable, but icons are fairly visible.
Frame rate dips, but it's far from being unplayable.
The third tutorial has an issue where you can't proceed with clicking something on a menu.

No bugs or problems making this game unplayable on my hardware. Most of the time >30 FPS, in tunnels often >60 FPS
AI Flexity Trams sometimes miss one or more bending segments and departure monitors at stations sometimes flicker.
Pressing F12 for Steam Screenshots successfully takes the screenshot (and saves it silently, i.e. without notification) but also crashes the game immediately.
At this state, game is completely unplayable
Game has much lower FPS than Windows and after few stops game freezes completely
Runs out of the box on proton 5.13-6
If you plan on using a joystick, apparently you need to use current proton experimental (as of 2021/03/24) and connect your controller AFTER the game has loaded.

Works with all its current bugs reported for Windows
Crashed my Desktop to the login screen pressing Alt-Tab. Window size selection does not work. But I was able to set window size in ~/.local/share/Steam/steamapps/compatdata/1314140/pfx/drive_c/users/steamuser/Local Settings/Application Data/TramSimVienna/Saved/Config/WindowsNoEditor/GameUserSettings.ini
As usual for wine/proton the videos do not work. At the first run after the installation I had to click on the empty screen to get a video player twice which didn't play anything. After that the main menu was displayed and the game starts with the main menu from now on.