Penthouse is more of a mystery/thriller drama with 3 seasons. I definitely enjoyed watching this except there are a lot of sensitive things such as bl00d, de4d bodies, and more.
This is the BEST show to watch if you want to watch a K-Drama with a mystery/thriller genre! (IMO)
There are A LOT of plot twists and I'm sure you'll be shocked because those plot twists are mostly UNEXPECTED! Even my mom got shocked lol!!

For example, Yoon-Hee was the true murderer of Min Seol-A. From the beginning of the story, it already has a lot of mysteries that need to be uncovered, and if you solve it before the drama uncovers the mystery, you probably can be a detective haha!

There are a lot of interesting characters with different and unique personalities that make the show very unique.
The plot is very good especially since there are A LOT of plot twists you would NEVER expect. IMO, the show makes sense and the truth is way more shocking than you think. (Especially for the first season!) I got really excited while watching this, I really wanted to know who killed who, how that happened, etc.

Though the ending... I really didn't want Su-Ryeon to die. She didn't deserve it. SSR is a very kind person but she can't control her emotions which led her to do bad actions. Logan gave her a vest at the end in case something happened. But, she didn't use it.. It made me really sad..
I also think Yoon-Hee didn't deserve to die. All she wanted was for Rona to be accepted in Cheong-A. Yes, she may be selfish but she's a mother, and a mother would do anything for her child to be happy.
I have no reactions to Seo-Jin and Dan-Tae's death TBH. They both deserve it because they were the real villain.
ALL THESE ARE MY OPINIONS!