First of all I write this review not to hurt the author but to give him my personal opinion on the story and so that he can improve it.
At first, I find it good but not at all developed enough whether it is the world that surrounds the Potter twins before Hogwarts or the characters themselves.
I think you should revise the development of the world even if it is inspired by other Harry Potter fan fiction.
Concerning the development of the characters, it's almost empty of course if you saw the Merlin series and the Harry Potter movies, you can imagine them but the story doesn't develop them at all.
As far as writing is concerned, one problem would be the text blocks that I find really horrible but otherwise on the whole at the level of spelling it is not too bad.
Before the conclusion here are several advices:
The first advice is to make character sheets for each character because it will help you to develop them in your story.
The second tip is to take your time because currently the story is in the 11th chapter and you are already at Hogwarts while you could have approached a huge development of character and history in the changes that Jake has brought in the childhood of Harry.
The last piece of advice is if you want your story to attract publishers you need to write much longer chapters.
In conclusion, despite all the problems mentioned above, I think the story has real potential so keep going.