Nintendo and nostalgia seem to go hand in hand as of late. If it is not a direct sequel to one of their immensely popular IP's such as Mario or Zelda then it is a spin off that features the characters. This seems to always be the case. They might put New in front of the title much like they put Super in front of sequels on the SNES. The point is that they are doing the exact same thing they did almost three decades ago.
This is not the only thing Nintendo used to do in the mid 80's that they are still doing now. Since Mario was such a hit Nintendo decided early on to put Mario into any game to help sell it. Even other companies could do this.
This practice was done constantly. For every one authentic Mario game there was Famicom Grand Prix: F-1 Race or Mario Paint. Instead of just simply making a racing game, or a paint game Mario was slapped on the cover and in the game so it would sell more. The only purpose mario has in these games is to help sales. Nintendo still does this today. Here is some food for thought. Would Super Mario Sunshine have been a lesser game if Mario was not in it? If, instead of Mario there was a new character that they created with the same gameplay and visual style. A platformer with a squirt gun thingy, why not make it a new character? Simple, Mario sells more. That is the only reason.
Or how about Super Mario Galaxy? A fantastic game, but why Mario? Could this great game not have been a perfect opportunity to introduce a new character and world? Does anyone honestly believe that the game improved because it was Mario, that it would have been a lesser game had the character not wore the red hat?
Finally it seems that Nintendo will even borrow levels in their future releases. I recently saw this image posted and feel it does a very good job of showing the recycled material.
This practice of reusing levels has been done since VS. Super Mario Bros. reused levels in 1986 and here is Nintendo still doing the exact same thing. Reusing levels and characters is not done to save money but instead done to reduce risk. By rehashing a great game that everyone enjoyed there is little risk that it will not be liked a second time around. This is no different than the yearly sequels we see today from other companies. It's very risky to put millions of dollars into a game that might flop from a business standpoint but it must be done or the short term goals will prevent any long term viability
The fact is that Galaxy and Sunshine were great games and would have sold well without Mario. It is commonly understood that the quality of Nintendo products is top notch but they are simply too afraid of trying something new when they can just stick Mario on the cover. This fear is why there have been over 10 Mario Parties. This is why they are reusing levels from old games decades later. Nintendo is too old and stuck in its ways to change. Once faced with financial hardships they do the opposite of what is needed. They slink back even farther into the mindset of sticking with what sells instead of innovating. They begin to tell scary camp fire stories of creating new experiences with new characters. It's not too late for them, but they need a bigger wake up call than one bad year.