"Mario, please come to the castle. I've baked a cake for you. Yours truly, Princess Toadstool." 
"Wow, an invitation from Peach! I'll head out right away. I hope she can wait for me!" 
Mario is so excited to receive the invitation from the Princess, who lives in the Mushroom Castle, that he quickly dresses in his best and leaves right away. 
"Hmmm, something's not quite right here... It's so quiet..." 
Shaking off his uneasy premonition, Mario steps into the silent castle, where he is greeted by the gruff words, 
"No one's home! Now scram! Bwa, ha, ha." 
The sound seems to come from everywhere. 
"Who's there?! I've heard that voice somewhere before..." 
Mario begins searching all over the castle. Most of the doors are locked, but finding one open, he peeks inside. Hanging on the wall is the largest painting he has ever seen, and from behind the painting comes the strangest sound that he has ever heard... 
"I think I hear someone calling. What secrets does this painting hold?" 
Without a second thought, Mario jumps at the painting. As he is drawn into it, another world opens before his very eyes. 
And so begins the grandest of all adventures! 
Once inside the painting, Mario finds himself in the midst of battling Bob-ombs. 
According to the Bob-omb Buddies, someone...or something...has suddenly attacked the castle and stolen the "Power Stars". These stars protect the castle; with the stars in his control, the beast plans to take over the Mushroom Castle. To help him accomplish this, he plans to convert the residents of the painting world into monsters as well. If nothing is done, all those monsters will soon begin to overflow from inside the painting. 
"A plan this maniacal, this cunning... this must be the work of Bowser!"
Princess Toadstool and Toad are missing, too. Bowser must have taken them and sealed them inside the painting. 
Unless Mario recovers the Power Stars immediately, the inhabitants of this world will become Bowser's army. 
"Well, Bowser's not going to get away with it, not as long as I'm around!" 
Stolen Power Stars are hidden throughout the painting world. Use your wisdom and strength to recover the Power Stars and restore peace to the Mushroom Castle. "Mario! You are the only one we can count on."