Hello

In case anyone stumbles upon this issue: it looks like this is gamemaker's problem (the engine used by this game).
If you have two displays, change their configuration untill game launches properly. After that you can restore your original config

In my case I have laptop with external monitor and first display (laptop) is disabled. To launch LoopHero i have to reenable it: start the game, and disable just after the launch


For completness: the "not moving hero" issue can be fixed just as stated in other posts by changing locale to C:

export LC_ALL=C
./start.sh

or you can add this export LC_ALL=C into the start.sh script


both of this issues should be fixed by gog and developer...