Why are controller options so restricted on NSMBU?

My kid wanted me to play NSMBU with him, so we started the game, he had the Game Pad and I picked up a Wiimote + nunchuk that was around.  This is how we play SM3DW together.  This doesn't work!

1st thing I realized that it forces you to use the Wiimote in horizontal mode instead of letting you use a nunchuk.  Sucked, but ok I can deal with that.  Then we realized NSMBU lets you play single player on the Game Pad, but if you want to play multiplayer you can't use the Game Pad as one controller.  What were they thinking .

It's already annoying we can't use the Game Pad in Wii mode... but we can't even use it to play multiplayer on a Wii U game??  Or am I missing something?  In the end I had to tell him to play by himself.

No, you're not missing anything. It's a terrible design choice. The gamepad can be used to create playforms in multiplayer - so cool, I know.

Are you sure? I'm like 99% positive that I played multi-player w/ my kid and we used on Gamepad and one Wii Remote. Make sure you're not choosing boost mode!

this game is plain stupid

I bought a wiimote to play 2 player it doesn't work. you need to buy 2 wiimotes just to play multiplayer

why are you allowed to play single player using gamepad but to play 2 player you need 2 wiimotes? its one of the most pathetic things I've ever seen in gaming

I also heard you can't use the Pro Controller. No sense it makes!

You can't "choose" Boost Mode, if you choose Wii Remote instead of single player GamePad, it's automatically Boost Mode. It sucks.

You couldn't before no, but since the New Super Luigi U release, you can download an update.