roa2-start script is not really seen as a shell script, adding #!/bin/sh as 1st line solved that and it at least gets executed from the shortcut.
After doing that the script returns the error: roa2-start: line 3: 7567 Segmentation fault ./runes-of-avalon-2-demo, same as when starting from the installer

removing the LD_LIBRARY_PATH line solves it and runs the game, so I am guessing you get the segment fault because your included library’s don’t work to well with those default on my system, without the new path I think its uses the defaults on my system and works fine.

Of course I could simply execute runes-of-avalon-2-demo and not use the script at all since by removing the path line the script does noting extra

Some more playing around:
1- you point to gfx/wrapper/gfx/go_to.png but that file is not included
2- I dragged runes-of-avalon-2-demo, sfx, gfx and data to a new location and the demo runs fine without any of the lib’s

I am not an expert on this library stuff, I can just say that without them it works fine, using them via the LD_LIBRARY_PATH does not work. You got my mail if you want to contact me about some more tests.

As for your question about the installer, I do believe that a good installer (and have no issues with yours) makes the whole experience better for linux starters or none geek users You might want to move the shortcuts one step lower inside Games and not in the root.