Are both the files from the zip archive present in that directory? There should be a .pck file as well as the .x86 file.
However, the message you're getting is more like the .x86 file is not actually there. For example for me (on Ubuntu) I get the English equivalent of that message if I remove the .x86 file:
bash: ./Guerrilla Gardening 0.5.x86: No such file or directory
But if the .pck file is missing I get:
Error: Could not load game path '.'.
All I can suggest right now is to try unzipping the archive again and make sure both files are present.