itch.io

For anyone importing this into Unity, make sure to copy the settings down below so the sprites do not get blurred by the compression in Unity. Make sure the Pixels per unit is changed to the appropriate value of sprite size.

I don't think using open source tools requires you're project to be open source as well. That only applies if you were to use the character generator itself in your project not just the assets created by it. If that was the case, every art project made in other open source tools like GIMP would have to be open source.