I don't believe I've seen the other parts. This seems like a fine series. The animation could be better. I will admit that the ideas are pretty creative. I'm especially impressed by the spider legs on the half corpse. I've always loved spider legs for some reason.
The voice acting is alright. It's just not the kind of thing for me. You still get pretty good exposition. I probably need to see the other parts to know more about it. That's pretty obvious.