Originally Posted by Storm
Hm, just to make things clear: If I play through the game, then go to the mission replays, it'll take my best attempt at the mission and upgrade the final score?
Yes. The game will upgrade your best hit on every subscore and finally increase your Overall Completion Score (the score for beating the game) accordingly, but it won't do this on your every mission's completion score.(In other words, for each specific mission, you have to get a higher score to overwrite the former one.)