why not you keep everything the same, but with new levels and plot twists?
btw, why not reveal more of those other 'sorcerers' that were mentioned in the game?
That's where the issue is, the combat system doesn't allow for much twists beyond adding debuffs of time limits. If this was to get extended to a 2-hour game, it would become incredibly repetitive after a while. As for the "sorcerers" and the monsters, they already have a story in the sense they are a metaphor for a (SPOILERS, and generally unpleasant stuff) real thing.