The characters:
The protagonist is supposedly over 30, yet acts like a child. The only motivation for the MC seems to be some promise between him and his childhood friend, which is just seriously weak and small as a premise. The characters are intensely stereotypical with little depth.
The story:
A typical shounen masquerading as something more. Lots of seemingly convenient but illogical events happen and no explanation is given.
The storytelling:
The world seemingly revolves around the protagonist, and the death and destruction/background is de-emphasized.
The only strength of the anime:
The Kaijus are well-designed, but they barely get any screen time when the fights end with a single blow.