This review is only for one of the stories in this; the sixth one, "keyhole". I couldn't find scanlations of the others. Keyhole is about a doorknob characterized as a woman. This doorknob's "keyhole" is her clitoris. I only read this because it looked fucking hilarious; and I sure did get a whole bunch of laughs. I never expected people to find doorknobs sexy.
The character's shit, but most hentai as shit character anyway - so this is no exception. Besides, hentai readers and viewers don't give two shits about character - they care about how big the tits are.
The art's fine, but nothing special.
If you actually find this kind of shit sexy, I guess the naughty parts have good detail.
But I found it enjoyable in a laughing-at it, not with it, way. It's quite... creative. Unlike the colour green.
By the way, I'm a vagina-owner and I can tell you that sticking a key into someone's clitoris would fucking hurt.