I mean it's alright, but it's also very very weird, and not always in a good way.
Before we begin, if you like yandere monster girls, this is definitely for you. The ending is pretty sweet, and the relationship between the MC and the heroine itself is pretty interesting.
What makes me give it a 7 instead of an 8 is the otherwise pretty mediocre story. To be honest the only reason it's not a 6 is because I'm a sucker for weird romance stories that end in marriage/kids/what have you.
The story is just absolute gore nonsense, BUT a very fun and entertaining one. Aliens, crime detectives, alien human baby combos, yandere monster girls; it's not really surprising that a story containing all of these gets a bit too bizarre sometimes, and it does.
Otherwise solid piece of manga.