Hi tetrahedra, the game stores its saving file in your Registry under the item: Computer\HKEY_CURRENT_USER\SOFTWARE\Unity\UnityEditor\WetDogs\DogXBloods
You can remove this registry by typing 'regedit' in the search box on the taskbar, then selecting Registry Editor (Desktop app) from the results. Then search 'DogXBloods' and delete it.