|If you want to play on HumbleBundle edition of Torchlight you need old libSDL2 library.|
|Someone forgotten about that.|
|With latests libSDL2 it won't work. You will have issues with mouse pointer.|
|Cursor will have black outline. You won't be able to click on anything etc.|
|So I prepared modified libSDL2 lib which will able you to play this game with no issues.|
|That's those libSDL libs. You need to copy it to lib64 dir where you've installed Torchlight, in my case it was /home/kkszysiu/.games/Torchlight/lib64/|
After doing some research I managed to find how to rebuild it. Basically it's not the official 2.0.0 but several changesets in the past, where the mouse support ABI was different.
The installer (Nixstaller) checks for dependancies before extracting libs, and if libSDL2 is already installed in your system, it will skip extracting it
Here is a workaround to get the proper version of libSDL2 packaged in the installer.
Then, move libSDL2-2.0.so.0 into the /lib64 directory of your torchlight installation.
You can now delete /torchlight-tmp directory in your home folder.
All credits to Nel for share with me this fix.
The extraction from the package works perfectly for Ubuntu-18.04.2
Update: Tested on Ubuntu 20.04
Just Download Torchlight_fix_Missing_libSDL.tar.xz
Here is the FIX > Torchlight_fix_Missing_libSDL.tar.xz