The first game was so bland and boring. It had a few good humorous moments but it felt so 'artificial'. If you didn't have the context of the creator literally crying at E3 it would seem like the most inhuman product imaginable. Bland writing, ESPECIALLY bland music and a fairly repetitive set up. Good gameplay though. I think it says a lot that most of the discussion online is still about how "surprising it was that it was decent" and not whether or not it's actually a great game.
No, it wasn't just decent, it was a damn good SRPG game. Did you expect a crossover between Rabbids, who communicate only in screams, and Mario characters to have a rich and nuanced story? If so, I think the problems lied with your expectations.