When it was developing the upcoming Mario game, the character's creator Shigeru Miyamoto says that the game had a *slightly* different temporary title:
Super Mario Galaxy 1.5.
But as Nintendo was making the game, the developers kept coming up with new and interesting level designs and ways to play. The game features new spins on the franchise with the likes of Cloud Mario and Rock Mario. With over 90 percent of of the level design being brand new, Super Mario Galaxy 1.5 naturally became Super Mario Galaxy 2.
And while Super Mario Galaxy 2 will come with a DVD that will help new players get up to speed, Miyamoto noted that the game itself is not easy. (Something Kotaku's preview noted.) In-game, green hint televisions will provide...hints to players.
社長が訊く『スーパーマリオギャラクシー ２』 [任天堂]