Hey, I got the error "Couldn't find a valid ICU package installed on the system." on Ubuntu. I managed to fix it by going to the terminal and doing:
export DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1
./SonOfRobin.DesktopGL
Thanks for valuable info. I will look into this issue (I've been testing Linux version on Ubuntu, this is weird).Have fun playing the game!