I never thought there was anything particularly difficult about Sonic Lost World on the Wii U, but apparently some people out there don't agree. As a result, SEGA has rolled out a fan-centric patch that allows you to earn extra lives with every collection of 100 rings, and every "game over" will net you 10 lives instead of five.
You can also control Color Powers with the analog stick and buttons (instead of just the touch screen), which is a welcome change. The patch also fixes a small graphical issue in the Frozen Factory area of the game.
So yeah, not a huge change, but it makes the game a bit easier.
Sonic Lost World for Wii U Gets Free Update [Sega Blog]