Well, like the other harem-type animes,it has a clouded ending.
In fact the story line was pretty good, except the part that the main character is from the beggining the over-powerd guy.
Overall the anime was good, deserves a try, nice character development, lots of funny things ( dont know which ep was, but i crashed with my chair laughing).
About the mecha part... they could've make it better... but is still worth the time:)
ENJOY