well, Castle Crashers has allot of humor in it, so I knew when playing it the ending wouldn't be too serious.
Me and my friend love to play it together ( even though his character is like, over ten levels above me and wins each princess ) and that increases replay value when you have a friend to go along your adventure with.
I don't know if its just me, but I do sometimes like a bit of repetition, when what I am repeating is fun.
I also noticed most of your cons seemed to be based around the games ending.
I guess you were pretty pissed about that.
Castle Crashers isn't the best game ever that's for sure, but it is up there in the great beat em ups of all time for its humor, violence, gameplay
( bear holding a fish ftw )