Hey Sloth, thanks for your interest!
This may be an unfortunate side effect of the game being developed in and old version of GameMaker. Is it a Windows Smartscreen pop-up you see? If yes, you can select "run anyway", and it should be fine.
We'll look into getting the game file signed to (hopefully) prevent alerts from popping up (even if this isn't 100% gauranteed to fix the issue).
Sorry for the inconvenience, and if you decide to play, please let us know if you encounter any bugs or issues!