Yeah, that hardware config should be certainly enough.
Sorry about the problem. If you feel like exploring this further, can you see if there is Player.log file in the following folder:
$XDG_DATA_HOME/unity3d/ColdwildGames/RebelStory
?
You can also try changing -force-glcore42 to -force-glcore32 or -force-glcore44.
Sorry again and thanks for letting me know.