The success of games like 'Mario' and 'The Legend of Zelda' stem from the continuity of the staff, according to Takashi Tezuka.

Takashi, who is a producer on the 'Mario' series, believes that the the tenure of the staff involved is one of the key reasons for the success of the gaming franchises.

Takashi told Game Informer: "May of them have been working on these franchises for a long time.

"For example, Mr. [Eiji] Aonuma became a part of the 'Zelda' team at some point and has been there throughout, and for 'Mario', it's myself! I think something that's very important to the 'Mario' series, of course, is the level-design philosophy."

'Mario' debuted in 1985, and Takashi believes that the design philosophy of the franchise has also helped to keep it popular.

He shared: "When we're creating every individual course, we just keep iterating, we keep looking, working on it until we believe that it's interesting; if it's interesting to play or fun to play, it's because someone made it fun to play.

"A major characteristic of side-scrolling 2D games is that you can still make changes to the course during the final stage of development. Of course, this cannot be achieved without excellent course editing tools.

"I think it's important to have tenacity and continue to strive for improvement until the very end, referencing feedback from focus groups."