The first thing I want to say is that if you can't withstand a cliffhanger,then you should drop the idea of watching this drama as it was released in 2017 and it's already been 2020. So second season's chances are almost nil.

Let me give you a honest review.

The concept of this drama is totally different. Different from every game drama.

Story:-

Story is simple. ML and FL are in relationship from 1 month. Then there was a man who died mysteriously and he was solving quiz or riddles with his friend related to the game. Suddenly FL disappears from this world and her memories from everyone's mind also vanishes except ML and his friend. Then they went inside the game and game starts. ML motive is to find his girlfriend who is stuck inside that game. He tries to overcome each level and of course he succeeds. A person dies in real world if his point gets negative.
The game is like a different parallel universe where you can use the game's card to buy anything. Everything there is just an illusion.

At the end ML finally saves his girlfriend and went to challenge the game Die Now and few of them were finding what an evil organisation is this and where is it located. Then the twist came that the girl ML saved is not the real FL but the illusion one and that organisation is in space. Yes, not on earth. Simply it can be said that this was an organisation made by the aliens.
And the story ends with a cliffhanger as the ML went to challenge the game.

But the story and the concept is great. Different. Sometimes a little funny.

Another thing in this drama is that the game only contains puzzles and mind tricking things.
As I expected some action too, and there was none, I was a little disappointed.

So if you are not afraid of the cliffhanger, you can surely go for it. It will not dissapoint you.