Majora's Mask isn't as good as Ocarina of Time, but is still an exceptional game.
Majora's Mask begins just after the end of Ocarina of Time. Link has returned to his child state after defeating the evil Ganon. For the entirety of this game, you play as young Link but you can use some of the items that Adult Link in Ocarina in Time used like the Hookshot and the Hero's Bow. The game takes place in the land of Termina, which Link goes to in search of an unnamed friend (supposedly it's Navi after the two parted ways at the end of Ocarina of Time but this is never explained). While traveling through the woods on Epona, Link is ambushed by the Skull Kid, an imp wearing a mysterious mask. Along with his two fairy companions, Tatl and Tael, the Skull Kid steals Link's Ocarina of Time and rides off with Epona.
Link chases them into Termina but is turned into a Deku scrub by the Skull Kid. However, while leaving, the Skull Kid abandons Tatl who has no other choice but to join Link. While in the caves under Termina, Link meets the Happy Mask Salesman from Hyrule. The Salesman tells Link that he has the ability to turn him back into his human form but to do that, he has to reacquire his Ocarina. In exchange for this, he asks Link to retrieve the Skull Kid's Mask, known as Majora's Mask.
As Link returns back to his human form, he learns the Moon above Termina has abandoned its original orbit and is set to crash into Clock Town, the center of Termina, resulting in the destruction of Termina. This was caused by the Skull Kid using the power of Majora's Mask after stealing it from the Salesman. Link learns that he has to awaken the guardian gods of Termina, the Four Giants, from their imprisonment and sets off on another epic journey.
Because the moon is set to crash in three days, the overall gameplay has Link traveling back in time to the beginning of the three days in order to find out how to stop the catastrophe. So far as I know, you keep all the weapons you acquire in the game but you lose ammo (ex: bombs and arrows) and all the rupees (aka money) that you acquired over the past three days. I do admit that this is really aggravating because you have to recollect everything you lost all over again and that's a pain in the ass even though you keep everything else.
In Ocarina of Time, the masks were only a sidequest as you tried to find people to sell them to. Here, they are more important. Each mask in the game has a power that helps you in the game. Three of these masks, the Deku, Goron, and Zora masks, transform Link into those creatures. Each form has its own abilities. Deku Link is able to shoot bubbles, do spin attacks, and fly for a short amount of time with the use of Deku flowers. Goron Link can use his strength to fight enemies and can also roll at high speeds. Finally, Zora Link is able to swim underwater, walk at the bottom of bodies of water, and can generate a force field.
Just like Ocarina of Time, Majora's Mask uses the concept of traveling through dungeons and fighting strong bosses. Both of these games work well on the N64. The controls work well and as always these games look excellent.
So why is this game not as big of a masterpiece as Ocarina of Time? Well, why this game does retain the sidequests and minigames from Ocarina of Time, Majora's Mask actually focuses on them more with some being essential to the player completing the game. If you have a problem with one of the minigames, it might prevent you from completing the game. Of course I have to talk about your fairy companion in this game. No, this isn't a complaint because Tatl isn't annoying like Navi. Navi's extremely annoying 'HEY!' and 'LISTEN!' is now replaced with a much calmer dinging sound. This is an improvement over Ocarina of Time and it is an advantage Majora's Mask has over Ocarina.
So, Majora's Mask isn't as great as Ocarina of Time, but it stands as another good game in the Zelda franchise. Both N64 Zelda games confirmed one thing: Zelda succeeded in the 3-D era of gaming and will likely never go extinct.