Mario and the game you reference are copyrighted and protected content, so using them without the consent of their owners is illegal.
If Nintendo sues you, you have no chance of winning.
That being said, there are companies that allow fan content and others that don't. The internet is full of stories and projects similar to yours that have had to shut down after a cease and desist letter and at the same time there are tons of projects like yours going around. There are cases where the companies have hired the creators or have even licensed the content.
For these reasons, many people think that it is a gray area, but in reality it is not. Using other people's content without their permission is illegal (except for fair use, but that's another topic). and you always run the risk of receiving a cease and desist letter and losing the work you have done.
If your game doesn't sell or gain some popularity, it's very unlikely that you'll catch the attention of the company that owns the rights. But if you want to sell, or protect your work, then you must own (or have the permissions for) all content in the game.