I really like that the MC, how do I speak? A human MC, the confusion, doubts, and changes of thought. We are this, the human change and mature with the time and this include the adaptation.
The game body and mind is not overly excessive as other novels, that the MC turns plain and cold with immortal body, this is a good point for me, but a bad point for you.
I think that the MC, it is important that you (Author) show the though process about the action and objectives of the MC, I don't know if there are another objectives beyond to survive the Uchiha Massacre... Well, the quests maybe to direct him, but is important that he has own objectives.
Wow, thank you for the novel, I am enjoying every much!
Keeping the good work!