I honestly think the only reason James Franco and Seth Rogen agreed to be part of this messy movie was the financial one. No actor who wants to build a serious career (and even if this career is acting in comedies) would agree to be part of such a thing.
Not only the movie is not funny, but it is filled with annoying jokes (including numerous and unnecessary references to LOTR and ridiculous scatological jokes). James Franco's performance looks like a parody of himself, artificially trying to be funny.
Kim Jong Un is portrayed as a retarded fan of Katy Perry and margaritas. Seth Rogen does nothing but play himself - as he always does - and women in this movie are just portrayed as mere sexual objects.
Honestly, "Hungover" parts 1,2 and 3 are as classy as a violin concert compared to this movie that should have never been released. If it weren't for the Sony hack and its following drama, it would have never been watched as well.