I downloaded it and here it is normal, I haven't had any complaints about it either, I'm sorry I really don't know what the problem is, try using winrar maybe it will work
I took your suggestion and tried win-rar but it still didn't work.
Not really sure what to make of it. I have the latest versions of 7-Zip and WinRAR and neither seems to be able to extract that Ren'Py Archive. I also have the latest version of Python so it's not an issue there either. Just to check I also made sure to have the latest version of Ren'Py as well so I'm pretty sure it's not an error reading the file. If you have any other suggestions I would appreciate it and will give them a try.
Edit:
Just for the heck of it I tried using the itch app and it worked with no problems. I'm even more confused now but at least it's working so I'm going to try your game now.