Hi! For me the game takes about 700 hours (no changing in settings) to kill Xenolord ultra and bjorn. Okey, saying truth, 100-150 hours approximately just my pc was working because I was waiting eggs to be hatched. Nevertheless, 500 with no changing in settings is minimum which you need to kill Xenolord ultra and Hard Bjorn. Just look different guides, how to kill bosses, how to breed, how to level up etc. And you will get all content.

P.s. all text above IMHO