I can´t remember the whole list of games released in 2015 (not that it´s too long anyway) but I think it would be Yoshi´s Woolly World.
Even if the game was not what I was expecting, it´s still a great game and I enjoyed playing it everytime. And while the music was repetitive as hell, and not as charming as the snes game, I had some of the tunes stuck in my head for months! Haven´t played it on multiplayer, but I´m sure that it´s a very fun game for local multiplayer as well.
For 36,90€ (what I payed for it on amazon.es on release day) it´s a superb game and I would recommend it.
Edit: the poll wasn´t there when I answered, but now that I see it, my choice is the same. F*ck Super Mario Maker xD