Not to mention that the program that we use to compile it - Pyinstaller - isn't very commonly used for distributed executable files in the scheme of things (pygame is more commonly used as a learning tool, than as a tool for making actual games, because it has a lot of limitations - those same limitations are the reason why there were so many complications with the web version of the game & other complications), so this file looks very unfamiliar to windows. If you are not convinced about the safety of the game, you can view the source code on github, run it from source, or you can download the releases directly from github (these are the same files that are copied over to itch.io to distribute). Those those are the same files as here on itch.io, though, and will likely get flagged as well. https://github.com/ClanGenOfficial/clangen/releases
This game has been triggering antiviruses for a while, as long as I've been working on it, but to get this software signed is pretty expensive, and because this is a fan game and we don't own the warriors cat IP, it's all done by volunteers and we can't accept payments. Even the server that runs the auto-updater service is just run out of one of the developer's own pockets.