This is a well written and made movie. I didn't read the manga or saw the anime. So my opinion is only based on watching this movie. It has a quite good story with loads of room for the development for the characters. The story isn't unique but I actually really loved the 'parasyte' in the main person. Also they acted very good especially the main lead because it musn't have been easy to make a movie like this. The movie is gory it has blood and dismemberd bodyparts so it isn't for everyone, I didn't expect that but this isn't for the faint hearted. But this movie keeps you on the edge, you just want to see and know more so they know how to keep you hooked. There are also little funny scenes it it, but it is really acceptable. The special effects were great! I really liked those, it didn't look unrealistic at all. They did and amazing job in the CGI! The music was well chosen and fittend every scene. There is a second part coming so I'll be sure to watch that but I wouldn't rewatch this movie very soon just because it is quite gory. Watch this if you like science fiction/alien movies with gore. Skip this if you can't handle blood and dislike CGI movies.