Grand Finale Galaxy supplies the final commemorative star for each character. Finish the 120-star collection with Mario and Luigi, including the final Bowser clear required for the ending progression, then use the Planet of Trials to enter the finale.
The Star Festival
Explore the festival route through the Mushroom Kingdom and collect all 100 Purple Coins. Unlike the timed Purple Coin challenges, this visit lets you take your time. Sweep the landing area first, then follow the road towards the castle. Check both edges of the route and the spaces around the festival characters before moving on. Use a jump or backflip for any coins above the path rather than running past them.
Finish the collection
Work back along the road if the counter is short. The coins are spread through the festival scene; do not leave the level while looking for a different galaxy or a hidden combat challenge. Once the counter reaches 100, collect the Power Star awarded for the festival. Complete the same mission as the other character to bring both individual totals to 121.
Completion check
The save records Mario’s and Luigi’s collections separately. A 121-star Mario file does not mean Luigi has also finished the finale. Confirm that each character has their own final star after both 120-star runs. The finale is the final star challenge; optional observatory exploration does not add more stars.