Well, it might be a fanfic that takes the concept of life being a game and applies it to the Naruto world. So, the ninja characters could be leveling up, gaining new skills in a game - like system. For example, Naruto could be on a journey to reach the 'highest level' of ninja, with each mission or fight being a step in that game - like progression.
Since it's a Naruto fanfic, Naruto himself is likely to be one of the main characters. He could be the protagonist who navigates this 'game - like' Naruto world.
Most likely Naruto himself would be one of the main characters. He is the central figure in the Naruto universe, so it's natural for him to play a big role in the fanfic. Sasuke is also probably a main character as he is Naruto's rival and an important part of the story. Sakura could also be there, as she is often part of Naruto and Sasuke's storylines.
One interesting plotline could be how the characters' real - life relationships are affected by the game. For example, Naruto might struggle with friendships in the game that mirror his real - life challenges. Another could be the power - ups and new abilities the characters gain within the game world, which they then use to overcome challenges both in the game and in their Naruto - like real - life situations.
It could be Orochimaru. In this fanfic, he could be a player of the same 'life - game' as Naruto, but with a much more sinister goal. He might be trying to manipulate the game rules to his advantage, like finding a way to make all the ninja in Konoha his puppets. Naruto would then have to figure out how to stop Orochimaru's evil plans within the game - like mechanics of his world.
One possible interesting plot could be Naruto finding out that the 'game' has hidden quests related to his family's past. For example, he discovers a quest that leads him to learn more about his mother's clan and the special powers they held. This could add a whole new layer to his character development as he tries to master these newfound abilities within the game - like framework of his life.
Well, Naruto would probably be a very energetic and determined person in real life. He might be into martial arts or some kind of extreme sport, constantly challenging himself. And he'd surely be the center of attention with his boisterous personality. He could also be a great motivator for those around him, just like in the anime where he inspired his friends.
Naruto could be a peacemaker. His optimistic and friendly nature might lead him to try and end the wars in Westeros. He could use his godlike powers to force the warring parties to sit down and negotiate.
Perhaps in this fanfiction, Naruto's life is ruled by some game - like rules. For example, he has a certain number of 'lives' and if he fails in a mission, he loses one. He might also earn points for successful missions which he can use to unlock new jutsus or abilities. It could also involve some sort of a game - like ranking system among the ninja community.
It could be Orochimaru. He is always looking for ways to gain power and in a game - like scenario, he could be the main villain trying to stop Naruto from achieving his goals. He might set up various game - like traps and challenges for Naruto.