While the game is perfect for me, the game is not actually perfect. There are some glaring flaws such as the aforementioned frame drops and graphical issues on the older 3DS models, but the amount of good things in this game definitely outweigh the bad ones. I've had 153 hours of fun by now, and I'm getting ready to go on a quest with some friends as I type this. If this review has interested you at all, download the demo! It's free and gives a general idea of the game.
This game is definitely what the Wii U needs for a huge boost, and the popularity of smash probably is going to give it atleast some of that much-needed boost. It polishes everything the 3DS version lacks in, though gets rid of the underwhelming Smash Run game mode for the, sadly, even more underwhelming Smash Tour game mode. It presents itself really well through amazing graphics and music, but also through fluid, fast gameplay, but the lack of an adventure mode really makes this game lacks something. that said, go out and buy this game if you have a Wii U right now!