I haven't played altered fable. Its not in english
Kasumi together with Sumika and the twins Meiya and Yuuhi
True that the end of alternative is rather sad but that's cannon. For me if the girls manage to stay alive and the BETA is destroyed. That will be enough.,
The girls indeed deserved good ending but what about Takeru? his goal is to return home. Does he deserved to stay on a foreign world? His own Sumika from his original world not the altered world that is in brink of destruction thanks to his stupidity, is waiting for him.
Remember who Takeru is and where he really lives. His is not from the beta world.