Last as in, by its release date, not as in "I bought Mario Galaxy 1 in 2014", though I suppose you could add that too if you want.
For me, Epic Mickey 2, 18th November 2012. Bad choice; I enjoyed the first one but the second sucked the sweat off a camel's bollocks. Should've quit after the excellent Project Zero 2 Wii Edition in June 2012 and ended on a high note.
I feel your pain. Epic Mickey is one of the best games on Wii; the sequel was a hot mess.
Anyway, for me it’s Rodea the Sky Soldier (November 2015). It came bundled with the WiiU version.