Also, yeah, you're right, I didn't realise that. I do all side quests as they come up, so after that I head into Bowser's Castle quite quickly and finish the game, so 'the rest of the game' is hardly anything for me.
Then the remake should add a sidequest in town that opens up after you finish the game, so you're forced to relise it
By the way, I've recently watched a 10-year-old video, showing the ending and credits of Superstar Saga, and two or 3 comments were like: "are you kidding me? After that hell boss fight, that's the ending? So disappointing!"
And I don't get those comments at all.