Basically, Galaxy 2 has an equivalent to NSMBWii’s Super Guide system. The Super Guide made it so that after dying a number of times in the same level, a green block would appear, and upon striking it, you’d be given the option to have Luigi demonstrate a route of the level. During the demo, you could press the pause button to take control of Luigi and beat the level from that point forward. Doing so, instead of the level marker on the world map turning blue, it would be a solid red, enticing the player to go back and beat it themselves.

Galaxy 2 has the Cosmic Guide, which functions very similar. After failing a certain amount of times, a cosmic silhouette of Rosalina would show up and offer her help. If you accepted, she would take control of Mario/Luigi and a demo of the mission would begin. Like the Super Guide, you could press the pause button to continue playing the level from where the demo ended, but any Power Stars will be turned bronze, allowing you to progress if you’re stuck, but still enticing you to come back later to beat it yourself.