I haven't seen any reports of a drop in frames anywhere for the wii u version, but for me, When I burn a bunch of stuff together, I get a huge drop of frames.
Also the jingle cutscene lags alot, the cutscene wasn't lagging in the previous house I had the console in. Once out of the cutscene there's very low frames until you do something.
Any clue of what happened here? The cutscene stuff wasn't happening before.
EDIT: And then my Wii u just crashed, couldn't turn power off, the only thing I could do was open the tv remote.
I'd personally say it's something with your Wii U, or maybe even your power supply. If it wasn't lagging in another house but with the same console it probably isn't the game.
Can't suggest much beyond that though, sorry.
I did drop the console less than a meter before, Nintendo land was working fine, i just spotted some bug with the shadows on the hair. I have less than $30 and the console is just calling to be sent in for repair 2 weeks after I got it.