If you don't use a guide to find all of the masks, then it can be somewhat difficult. However, if we're speaking strictly in terms of gameplay, I didn't find it too difficult. It wasn't exactly easy, but I never found myself wondering if I'd actually be able to get past a certain challenge, or even using that many fairies.
The thing about Majora's Mask is that it assumes the player has gone through another 3D Zelda game before; there's no "beginner's temple", such as the ones found in the beginning of most of the other console Zelda titles where the puzzles are brainless and the boss can be beaten without really trying. Majora's Mask shoves you right in the middle of the came without necessarily giving you the time to prepare yourself. Those that have played other Zelda titles won't likely notice a difference, but if it's their first Zelda game they'll likely encounter some serious difficulty, and the rest of the series will seem easily by comparison.
The thing about Majora's Mask is that it assumes the player has gone through another 3D Zelda game before; there's no "beginner's temple", such as the ones found in the beginning of most of the other console Zelda titles where the puzzles are brainless and the boss can be beaten without really trying. Majora's Mask shoves you right in the middle of the came without necessarily giving you the time to prepare yourself. Those that have played other Zelda titles won't likely notice a difference, but if it's their first Zelda game they'll likely encounter some serious difficulty, and the rest of the series will seem easily by comparison.