I heard about Monstrum early 2018 from news that Lee Hyeri, one of the singers from now disbanded Girl's Day (K-Pop girl group), was going to be making her big screen film debut by starring in this film. When I heard it was going to be an action-horror, my interest was piqued. Honestly, the main reason I watched this movie is because of Lee Hyeri. I was pleasantly surprised she was given the female lead role, and did a very good job acting. The movie is a period piece, but it's not just an action-horror. There's elements of mystery and thriller, and even some comedy too. The movie had a nice pace with no dull moments. I really liked the fact that there was no forced romance either. It was kept to just a few lines too.
There were a few instances where scenes connect abruptly, with no segue. It was annoying but it doesn't ruin the story. My other gripe, which is a big one, is none of the main characters ever suffer anything tragic. A few dramatic moments, cuts, scrapes, bruises, and some hurt feelings. That's it. Regardless, it was still an entertaining movie. I hope Lee Hyeri will have similar roles in the future, as she did a superb job in this one. It saddens me that Girl's Day has disbanded, as they were one of my favorite K-Pop groups. But at least I get to see the next chapter in one of the member's life.