I recently picked up Sonic & All Stars Racing Transformed on the Wii U, and I'm really enjoying it. The levels look beautiful, the racers make me nostalgic, and remote play is totally awesome because my wife gets her own screen on the TV without having to split it.
Yep, everything was going pretty well for us, until we got to the boost mode challenge, and found it nigh impossible to beat. But it wasn't due to our ineptitude -- it turns out the game is actually glitched, and a number of required boost pads weren't showing up.
Sega has figured this out (in addition to a glitch with ninja tag), and has sent a patch to Nintendo for review (a free patch for Sega I might add!). In the meantime, you can fail the event on purpose, then skip it.