It's not Ocarina of Time, I'll give you that, but it's still a damn fine game in its own right.
However what makes MM shine in its own right as a game is the darker storyline and key new gameplay addition, namely masks. This is a real hit and miss feature; the most used of masks will have you wondering how you will play Zelda without them whereas the one-timers will leave you wondering why the creators' bothered. There are noticeably less weapons but some of the masks are weapons in their own right. The game itself is also far shorter in terms of the key story arc which has only 4 dungeons to OOT's 9 but it offers so many side-quests that you can keep on playing for hours after beating the game.
Visually MM is fairly identical to OOT in terms of gameplay graphics but is noteably sharper during cut-scenes as well as the environments with improved shadow and mist effects. Now the requirement of the expansion pack is the main contributor to this but its more than worth the investment to play this masterpiece.
In terms of sound MM ticks all the boxes with an impressive score of themes and melodies as well as just as many fun Ocarina tunes to play as OOT (the Zora's Cape and Milk Bar side-quests in particular). As with OOT the number of voices are minimal and is limited to simple grunts and shouting from our hero and simple noises for other characters but it isn't really a problem, especially for Zelda fanatics who are used to this concept.
The downsides to MM are few and none of them take too much away from your enjoyment. The one that seems to stand out the most is the idea of having to rewind time to save and doing so loses ammunition for all weapons as well as any rupees you haven't safely placed in the deposit bank. It is the resetting of virtually every plot device, side-quest and mini-game that is the major downside to this concept and involving yourself in something for 3 days and then having to begin from scratch can be a tad frustrating. Some gamers may also miss growing up but before OOT Link was always a child so it shouldn't take anything away from the game. Overall Majora's Mask delivers that sense of freedom, gripping story, intuitive puzzles, interesting characters (friend and foe alike), and superbly simple yet ultimatley effective control scheme that made Ocarina of Time the definitive game of its era. It even expands on a few of these concepts as well as looking better doing so but sadly it just isn't OOT. The time reversal concept and shorter plot takes away the near perfection this game so nearly acheived but it is nonetheless an absolutley outstanding game.