If you chose the bad ending, there is no "clean" way to restart the game, as some choices have consequences.
However, you can always reinstall the game from scratch to try again. :)
Ohw, so sad. Okay, I'm reinstalling the game. Thank you
ps. Your game is purrfect, I love it and in a strange way It helps me with depression, so thank you very much
Thank you, and glad it's able to help! ^_^