Overall, I felt like this show wasted a lot of potential. There were just so many problems, plot holes, and unexplained things.

The protagonist is so unlikable for the majority of the show, not wanting to do anything but play Kill-Balad.
The master plan for the villain doesn't make sense.
They never actually show the robot club building the robot. They just suddenly finish it one day for the first one, and then for the others it seems like JAXA basically comes in and builds it for them.
Monopoles falling from the sky? So random... And they just leave the monopoles out in a field for a few episodes. It is like the scientific discovery of the century and they don't tell anyone.
The Kimijima reports? They appeared to basically serve no purpose and were just an excuse for the protagonist to go around wasting time. Please don't tell me the master plan actually required someone to go solve the puzzles.
Missiles that use AR for guidance?!?!? That makes no sense and was really stupid. I would want my missiles to hit REAL things.
How is Kimijima supposed to be controlling Aki's sister? Mind control through the internet? The power suit makes sense, but the brainwashing, not so much.
We deleted Kimijima from the internet so now our rocket control panel is completely unlocked, hurray!

At least Kai deleted Kill-Ballad after he finally realized that giant robots are awesome.

I had high hopes for this show after Steins;Gate, but it really didn't stand up nearly as well. The characters just don't hold a candle to the Steins;gate cast (Kai vs. Hououin Kyouma, really?) and the plot seemed poorly written in comparison.

Still better than some of the stuff this season, but I just wanted it to be much better.

/endrant