Hi Deviless!
Once https://www.win-rar.com/start.html?&L=0 winrar is installed, you can right click any .rar file and select [Extract with Winrar]. Pick an empty folder and the game will work when running the unity .exe
You can also set all .rar files to open with winrar automatically. We will look into the itch client for a non-compression download option 😊