First of all, this animei only adapted 4 chapters; as the manga goes way more detailed and more in dept how the story really goes. My personal opinion; the manga was definitely better, so when you're actully interessed in the story, read the manga if you want. Since this is the anime version that basicly serves only as a hentai, I'll cover this one first:
Did you even heard about the Cambrian epoch? Did you ever heard about the Cambrian explosion? Do you like science-fiction? Do you like hentai? Do you like tentacles? If you have answered on all questions 'yes', I can present you a hentai you would probably would enjoy. This hentai is made by Studio Jam that also made the well known classic hentai series called 'Bible Black'. This is also my very first hentai I would be reviewing for on MAL, so please be gentle with me.
Story: 6/10 (Fine)
Have you ever heard of evolution or molecule engineering? Well, put the two together and we can get a hentai about bio-technology to manipulate the DNA information manually. Dr. Yamagishi discovered from the Cambrian period while he was experimenting with radiation waves and he tested it out on himself. Dr. Yamagishi is a bit obsessed to create a new human species that has attributes from creatures that existed in the Cambrian period (tentacles etc.) some 540 million years ago and he started to test it out on himself. But things run a bit out of hand...
Remember people, it's a hentai. There are a lot hentai that don't take itself seriously and only purely exist for pure entertainment even though this hentai really tries to have a actual plot if I must say. It's just you don't have to expect a masterpiece style of plot, however.
A minor nit-pick I have to share that the writers went a little to far off in the start of this hentai and told that the Cambrian period started 600 million years ago, wich is actully wrong. The Cambrian period started in fact aprox. 540 million years ago. Trust me, I'm a paleontology nerd myself. I mean, in 60 million years a lot can happen. A good example would the current Cenozoic era that exceeds just over 60 million years and only started when the infamous Cretaceous - Paleogene mass extintion happend 66 million years ago when the non-avian dinosaurs and many other creatures died off. It total approx. 75% of species went extinct and it only give rise for the mammals to have a harsh battle to concur the planet and currently we're heading towards yet another mass extinction... Yes, I get it. No teaching during a hentai review...
Art: 7/10 (Good)
The art-style is done quite good for being a 2005 hentai if I must say. Perhaps the best part of it all is that this hentai is not censored? I don't like my pixelated 2D anime pussies, you see. Did I made you interessed? Yes? Good.
Sound: 6/10 (Fine)
The sound however felt a bit off in my point of view, but who am I to judge? It's only two episodes of less than 30 minutes long and your ears won't bleed. I promise!
Character: 7/10 (Good)
The charathers however were quite good written. We have a mad scientist, a female scientist that has a main role in the 'story' with a rather dark past, our male main charather that's also a scientist and another female scientist that's dresses a bit skimpy. You know, I only watched this hentai to see scientists pork each other and have a quick few laughs out of it. If you ever think scientists can't get it on, well, this hentai proves you wrong!
Enjoyment: 8/10 (Very Good)
To be fair I really enjoyed this hentai and I only watched it mainly for the laughs. I only came accros this hentai and when I saw the name of this hentai, I was thinking about the Cambrian period. I actually wasn't that far off if I tell you.
Overall: 7/10 Good
In overall, I would totally recommend this hentai if you're into tentacles or when you're a paleo-weeb like myself and wanted some quick laughs.