This game is a masterpiece.
The only problems in the game design are the boss levels, that are extremely formulaic and often completely counter intuitive (particularly the labyritnth levels), the response is not 100% and some later levels have the tendency to put more precise plattforming, something mario controls and move dynamics are clearly not meant for
A lot of people complaint about the mario movement being broke and imprecise, most due to his little slide after the jump, but that seems intentional, and help the game to keep rythm and momentum, creating a fast paced plattform that feels dynamic. The level design, even with the limited assets and technical capability, have sufficient variety to sustain its lenght. I hate the use of term "outdated" for most games, and i don't think this game is outdated (even the ones you can claim that are significantly more simple compared to its genre, like "Dragon Quest" (1986), have design problems that were problems already in 1986. But "Super Mario Bros." keep up with most standard 2d platformers nowadays. The game is well designed all around and achieve most things that it's trying to do. Most of the problems stems from the same overall problems that early Nintendo games had: Creating higher difficulty. "The Legend of Zelda" (1986), suffers from the same, with its intent of creating challenge in its later part, causing the game to betray its design, sacrifice what makes the game good in first place and go to directions that are more based in try and error than in good and honest challenge. I would also argue that "Super Mario Bros." suffers less from its later part than "The Legend of Zelda".
With this circunstancial flaws, "Super Mario Bros." still to this date one of the best games 2d plattform gave us, and this explains why people play it more often than even arguably better games, such as "Super Mario Bros. 3" (1988). The only thing this game needed was polishness and some design and levels expansion (what wouldn't receive in its 1986 sequence, but would in "Super Mario Bros. 3"), to be a masterpiece.
The only problems in the game design are the boss levels, that are extremely formulaic and often completely counter intuitive (particularly the labyritnth levels), the response is not 100% and some later levels have the tendency to put more precise plattforming, something mario controls and move dynamics are clearly not meant for
A lot of people complaint about the mario movement being broke and imprecise, most due to his little slide after the jump, but that seems intentional, and help the game to keep rythm and momentum, creating a fast paced plattform that feels dynamic. The level design, even with the limited assets and technical capability, have sufficient variety to sustain its lenght. I hate the use of term "outdated" for most games, and i don't think this game is outdated (even the ones you can claim that are significantly more simple compared to its genre, like "Dragon Quest" (1986), have design problems that were problems already in 1986. But "Super Mario Bros." keep up with most standard 2d platformers nowadays. The game is well designed all around and achieve most things that it's trying to do. Most of the problems stems from the same overall problems that early Nintendo games had: Creating higher difficulty. "The Legend of Zelda" (1986), suffers from the same, with its intent of creating challenge in its later part, causing the game to betray its design, sacrifice what makes the game good in first place and go to directions that are more based in try and error than in good and honest challenge. I would also argue that "Super Mario Bros." suffers less from its later part than "The Legend of Zelda".
With this circunstancial flaws, "Super Mario Bros." still to this date one of the best games 2d plattform gave us, and this explains why people play it more often than even arguably better games, such as "Super Mario Bros. 3" (1988). The only thing this game needed was polishness and some design and levels expansion (what wouldn't receive in its 1986 sequence, but would in "Super Mario Bros. 3"), to be a masterpiece.