Itch.io games shouldn't need to be installed; just unpack and run. If that doesn't work like it should, ask the game creator, their comments are open. (And while you're at it, ask them to use a standard archive format such as ZIP; creators won't listen to us.) Assuming it's this game, anyway. If not, please link to it.
Viewing post in Trouble installing a game
Yeah, it's the same game. But every time I download it, it keeps saying I need to install it with an app installer. I also tried using RAR Opener to unpack the files, but then it says the files either do not work or that its a danger to my pc, and when I do run it despite the pc's warning, it still says the file was not found and that I should re-install the files.