Could you imagine if a game did that today that just reused literally the same sprites for a new game? Shit wouldn't fly without serious criticism.
I'm with Ram, while Majora's Mask is good, it's vastly overrated ESPECIALLY when in the same conversation as OoT.
While absolutely true, at the time the game was praised on it's graphics, as sprites aren't the only thing that's worth noting. They did require the memory expansions pack in order to get some of the more complex visual effects to work, as well as allow for more enemies and npcs on screen at once. MM, in my opinion improved on a lot of the mechanics in the game over OoT.
Majora's Mask had:
-A more robust time travel system, where the management of the speed, flow, and order of time, as well as manipulating events throughout time was essential throughout.
-Five essentially separate playable classes, each with their own side-stories to discover as well as their secondary mechanics being essential throughout the dungeons, and game (save Feirce Deity).
-A way more in-depth mask system, with tons of intriguing side-quests and secondary attributes that each add. ie: bunny hood adds speed
Still, OoT deserves the credit to making everything in MM possible, as well as the main game being a bit longer, with respect to dungeons. I just enjoyed the story, tone, unique features/improvements, and side-quests more, mostly. I want to say it's akin to ODST vs Halo 3, but I know a lot of people here hate that game..