This VN is really awesome.
A refreshing one, using some stereotypes but breaking others. I mean, characters are nothing exceptionnal but damn, storylines are just outstanding.
Expecting a flooding in such an underwater theme park was a cliche, and even if it's happen, the story goes so far from just this.
I can only recommend it, even if I still prefer F/SN (guess I'm more a fan of fantasy), it'll easily hit a 9,5 out of 10.