I think their should be save and skip features, but the story is amazing. It sucks that you can't save, especially since restarting warns you that save data will be lost.
SPOILERS/DISCUSSION:
Is sacrificing Jae the only ending that brings Reina back? Is there a way to get everyone back alive? Is there a way to send Amelia to the Never in her place? How much is the ending(s) effected by the choices you make?
Also, LMK if anyone finds the secret endings. I've only gotten each ending for choosing who to sacrifice.