A comment on the Mario Galaxy port and how they handle the controls - in handheld mode, anything that used the pointer before uses the touchscreen now. This includes menus and option screens with things like "OK/Cancel", where for some bizarre reason you're not allowed to use the analogue/buttons and HAVE to use the touchscreen. This works out a little awkwardly- it's annoying having to take my hand off the controls to paw at the screen, and for long sections using the magnet stars it's awkward that your hand obscures large parts of the screen. But I was able to get through the game with it only being a minor nuisance.

Mario's "spin" attack/jump that was waggle on the Wiimote is now just a button press on the Switch, it works fine, maybe better than the original.

The most annoying sections- and I don't know if this is true on the Wii version or not- are the gyroscopic control sections where you ride a manta ray or steer a giant ball around by tilting the controller. In handheld mode these require the Switch to be in a specific orientation, which is a pain if you're lying down or on a bus. Also, these sections just suck pretty hard.

I didn't try the game in docked mode so I can't really say how the controls work there.