Though I am new to the mecha genre and personally Its not a favorite genre of mine I did find this series rather enjoyable even if there were a lot of giant robot fights. So this is coming from someone who doesn't watch a lot of mecha.
The story starts off where we meet our "hero" Kouichi Hayase a middle school pushover kid who gets picked on by bullies every single day to some points getting saved by his childhood friends; Yajima and Risako. On his way to run an errand for his fond bullies he gets in an accident and wakes up next to a naked girl who gives him the power of Linebarrel. Due to his new strength and power he becomes a cocky brat who uses that power to punish the bullies who picked on him.
For the first six episodes its nothing but him abusing his new powers until he witnesses a death of someone close to him (Keeping it spoiler free as possible) which eventually leads him to JUDA an organization that fights for justice. Kouichi straightens up his act a bit making him a more bearble main character however he still has that cockyness to him its just not as bad. After some twists and turns towards the end of the series leads to enemies becoming allies to fight a greater evil.
There were some episodes that broke away from the main plot where they were nothing but nonsense comedy however I thought it was a nice way to show some humor in the series. The only thing I really didn't care for the fanservice they threw in there and it seemed every girl in there had to kiss Kouichi at least once.
Overall the animation was excellect there were some aspect where the animation was odd like how some of the noses were drawn and the twins hair I think could have been better bit those are some minor set backs for me.
I thought the sound was excellent and the music for the series fitted nicely though at first I wasn't too sure about the opening song due to it reminded me of one of the Code Geass ending songs.
The characters were well rounded however I really didn't care for the fact that at least three of the females had a thing for Kouichi which leads to drama which pretty much breaks off from the main plot which I was most interested in didn't really care for him forming his own harem.
The president of JUDA I enjoyed his character very much from how he ran things down to his practical jokes that eventually got Kouichi in trouble. He was one of those great comic relief characters in my opinion.
Well I gave it this rating since I think it was a great show. I still think other shows are better than it but I don't hate this anime. I think they were better off putting no fanservice in it because it was pointless and it just lead to pervy humor. Still think the story could have gone better but I still think it's a series to watch if you are a mecha fan. However, I am new to this genre so mecha fans may agree to disagree with me.