Suikoden
Yes there are plenty of movies where the protagonist is part of a kingdom and later finds that kingdom is evil and joins a rebel group and builds an army and goes in war with the kingdom the protagonist grew up in.
However back to OPs answer what makes this story more effective in a videogame. To personally build your army, talk to different characters, see your castle expand and have tons of dialog. Recruiting with loads of side quests, upgrading armour and weapons starting small to become a big army. That feeling is just different in a videogame where I feel it's hard to capture in a movie. A TV show does come close due to a larger runtime across episodes. But things like upgrading armour and weapons and walking around your castle cannot be done with TV of film.