Ahh yes, I had skipped over doing much on the backstory as most of the one's I've seen hadn't worried much about that either and they're quite large, or they go through more of the MC's backstory throughout the story itself when they talk more about themselves.
My assumption with that was for most part didn't seem many were all that concerned with the backstory unless it had more relevance to the current story.
However as for saying you couldn't understand nothing of it, that I found surprising as overall feedback from others I've spoken to enjoyed it and eagerly awaiting the next update, none mentioning my poor grammar or at least not to the extent you have.
That being said, anything released from 0.2 onwards will have been passed through an editor to ensure better grammar upon release, this was started after 0.1.5 and as nobody seemed that concerned with it, I felt it wouldn't worth re-releasing again for the grammar when people seemed to get from it what was intended.
Back on the topic of the backstory, I will look into this more and see what I could some up with, either adjust the Prologue or do the other idea I mentioned and bring more of the MC's backstory into conversations and possibly flashbacks of his old life while talking about it.