Many gamers, including those of us who consider ourselves to be accomplished gaming ninjas, find older Mario titles such as Super Mario Bros. 3 and Super Mario World difficult to finish. Thanks to scientific research, we no longer need to feel shame when the dreaded 'Game Over' screen appears.
According to an analysis of the 'computational complexity' of video games, the main series of Mario platformers from the NES and Super NES era can be statistically classified as 'NP-hard'. As far as we can understand it, the challenge and structure of levels in titles such as Super Mario Bros. 3 and Super Mario World can be mathematically broken down in terms of probabilities, and they fit the NP-hard classification: the study involved creating amended versions of existing levels to prove the theory. Similar proofs have apparently been made for the Donkey Kong Country, The Legend of Zelda and Pokemon games from the 8-16 bit era.
The study also claims to have proven that mathematical problems can actually be recreated in a Mario level, and if the gamer beats a customised level they've actually completed a calculation, albeit through gaming skill rather than academic theory. This means that these Mario titles can also be classified as NP-complete, which is good to know.
We may not understand the details, but what we do know is that retro Nintendo titles have been the source of a thorough scholarly paper. If anyone criticises you for playing too much Nintendo, just tell them you're completing complex mathematical equations.