hyperbole: excessiveness
immaturity: lack of serious treatment of a topic.
banality: unaffectingly clichéd or trite treatment of a topic.
A nadir, a low point particularly in one's career.
anticlimax: an abrupt transition in style or subject from high to low.
Depth.
Overdone or treacly attempts to inspire pathos.
Risible failure on the part of a work of art to properly affect its audience, particularly owing to
The ironic use of such failure for satiric or humorous effect.
The property of being mawkish.