Because it's a 3D version of the original 2D sidescroller games, rather it's very reminiscent of them. There's a time limit in every course, little to no freedom for exploration, extremely fixed paths, a flag at the end....too similar to how the SMB SMW games are. Though Mario Galaxy was linear, it didn't feel like a 3D version of a 2D game like 3D Land and 3D World are due to having different things to do in the same places. I think everyone needs to accept the fact that it isn't how we expected a 3D Mario game to be like. The fact that Miyamoto even acknowledged that they "still had the Galaxy series" says something about 3D World...







