This review is going to be specifically about the anime, as other reviewers have done a top notch job reviewing the manga that's been published thus far.
So, having just finished the second season of the Manga, I decided I wanted to rewatch the anime (it having been a couple of years, I couldn't remember much about it, other than that it amused me.)
So, when I first watched the anime some years ago, it was because I had just stopped watching another series on Netflix and now I wanted to try something different. I just kind of came across it, and I thought "Hey, this could be fun." And boy was I right. FYI: It was the anime that got me interested in the manga.
As stated above, yes, the series veers HEAVILY from the manga, and is much more light hearted, very akin to the first bit of the manga. I'm going to try not to spoil anything, but Tsukune meets the girls much quicker than in the manga (especially Mizore), but it's done both humorously and, more suprisingly, naturally. Each episode is faily self-contained, but there is an overarching story to both seasons 1 and 2, though less so in season 2.
There is, as stated above, copius amounts of fanservice, and and if you were to play a drinking game where you took a shot every time you saw panties...I doubt you'd survive past the first 4 episodes. But here's where the other shoe drops: Even though this series is much more light hearted and "fun" than the manga, the same themes that Akihisa Ikeda said were the themes of the series, such as everyone being friends despite their differences, shines through beautifully. More than being a typical Harem, to dumb to live guy, Tsukune slowly becomes the linchpin character and the main cause of peoples (well, monsters, in this case, ha ha) learning to come together.
Characters straight up deny their parentage in favor of their friendships with others, and the character development, despite there really only being a whooping 26 episodes between the two seasons, is suprisingly strong.
Was there a lot of wasted potential? Yes, there was. I would have loved to have seen a more faithful adaptation of the manga. But what I got was still a heck of a lot of fun and had some pretty epic moments as well. My suggestion? If you're looking for some laughs while still watching a decent anime, give it a try. Maybe you'll be suprised as well.