Compared to Wii, Wii U definitely wasnt casual console, Wii U also had too much 2D platformers. I wouldnt say its flopped, Wii U has instal base of only 13m and games stil sold around 1.5m, that's actually better attach rate than DKCR made for Wii.

And MK8 has better attach rate than MKWii. Yet MK Wii sold 4 times better.

Yes, MK8 has one of biggest attach rate in history of video games.

And a 1/4 of MKWii sales. Attach rate is not even a consolation price this time. Neither for Tropical Freeze.

1.5m for 2D platformer isnt bad in any case, espacily on failed console, but 1.5m for MK would be bad in any case.

It is considering that the excuse to make it in the first place was the sales of Returns and that a new IP made more than 3 times that amount.