Yeah, I am writing the novel right now, no worries.

Just saying that I got convinced to remove the "skill trees" by one of my friends, for the reason that it is unnatural in the real world, and it might cause a so-called BUG (AKA a cheat character, and I don't want that). So yeah, there will be game elements, and there might be a so-called hidden skill tree, but it isn't visible to either him or you the readers. Or anybody.

Instead, I will put up a so-called skill list that the protag creates for himself, as to keep tabs on his growing powers.