A character is always seen wearing a bikini, but is never shown up close or with much detail.

A character constantly fantasizes about Squid Girl, but it only goes as far as them being a couple, nothing sexual.

Squid Girl frequently uses her tentacles to fight off somebody, but this is always meant for comedic purposes.

In typical anime fashion, some characters get nosebleeds infrequently.

Squid Girl is sent to the surface to invade the world for ruining the environment, but nothing ever becomes of it. She only thinks about it every once in a while.

Uses of "piss" and one use of "ass".

Occasional uses of "damn" and "hell" in the English dub.

None.

Nothing is ever frightening or intense in this show. The only thing that may frighten some people is the imagery they use when talking about Squid Girl's invasion, but it's not to frighten viewers. It is there for comedy's sake.