All I have left to do is find two final Heart Pieces and then go do the end-game. I've been playing for roughly 10-12 hours, can't be certain.
That leads me to think that, yes, the game is too easy. However, I'm aware of something I felt during Skyward Sword as well, which is that perhaps it's only easy since I know what to expect from Zelda, more or less. It's like how I'm only good at Call of Duty: Ghosts because I've played the games for six years. Except I've been playing Zelda for almost twenty.
There are a lot of things in the series that you come to recognise right away once you've beat about four or five of the games and they make much of the process fairly straightforward. Some of the puzzles in the dungeons have given me pause, I'm glad to say, but since they're so short this will only ever really happen once, if at all. Combat has given me the most trouble because I am reckless and just like to get stuck in, but it's the same as A Link to the Past's combat, a system I know intimately, so it's not slowing me down. I've not died once in the whole game, although there have been some close calls.
All things considered, I think I would say that game is easy, but I would hesitate to say too easy. It provides a nice level of challenge that won't get in the way of progress but which still leaves you feeling like you've done something. Many fights are satisfying to come out alive of, there are enough puzzles which make you think, and the collectibles are well hidden without being cryptic. It's a nice balance for a hand-held game and I think it works. So, easy - yes; too easy - not so much.