I'm enjoying it too. Yesterday went to a second hand shop and sold a crappy Wii U game I got during the holidays. Decided to get Super Mario Galaxy 2 to obtain more store credit.
When I got home, I played the first world, getting all stars and coins (although it says I only completed one planet) and had a blast! My wrist started hurting xD so I stopped... this didn't happen with SMG1 - think I've gone soft.