It's possible but it takes time. I suggest find a good artist and maybe someone that helps with modding.
Recent community posts
Yes, it might have something to do with the itch.io app if you are able to start the game directly. However, I assume you are successfully able to start other games!?
What you could try (not sure if that's the case?) to move the itch.io app/game to a directory with only ASCII characters. E.g. from "C:\Über\..." --> "C\Uber\...". Not sure if that's where your games reside? If you have only ASCII characters for the game's path, it's odd that that error message would happen however. Maybe try to talk with the itch.io team as well?
It seems the game doesn't like that path. However, generally, you given it's the portable version it should work in any path. Do you have any special characters in the install path of the game? Can you move the path in itch.io?