If you played the first South Park Stick Of Truth game (Fractured But Whole is not worth playing), then part of the pleasure comes from the cut scenes in equal measures to the pleasure you feel when playing. The game is less about overarching narrative and is more about enjoying time with your favorite Final Fantasy and Disney characters. There is a running story line between all the Kingdom Hearts games, but it takes little more than a bit of plot reading on Wikipedia to catch up on what has happened previously.
You fight your way through RPG areas with your cartoon comrades and use the key to seal the world off against evil cartoon characters. Kingdom Hearts III is similar to the other games where a character wields a key that blocks an invasion by dark forces. Evil cartoon characters fight against Square Enix and Disney characters in RPG and combat games/missions. Kingdom Hearts III continues with the same story as the previous games where the power of friendship is used to defeat the looming darkness. Softonic review The battle against darkness continues