Mario creator Shigeru Miyamoto has said in an interview with ONM that Super Mario Galaxy 2 will be a "really challenging" game.
He also admitted that he isn't sure the Super Guide from New Super Mario Bros. Wii will be in the game.
"As far as the challenge of Super Mario Galaxy 2 is concerned, I think it's going to be a really challenging game, but whether or not we are going to incorporate the Super Guide, I just cannot tell.
"In general, wherever and whenever appropriate, I think we will want to incorporate that kind of thing, but I cannot commit to anything specific right now," said Miyamoto.
Galaxy 2 is out in 2010.