This is the first time I've had this feeling of tiredness after watching a series.
A feeling of having watched double the number of episodes. But this is positive because this oppressive atmosphere is desired by the series. From the start we dive in and find ourselves trapped during this week of horror in the life of Yim Si Wan (perfect performance).
Between work (brighter atmosphere) and the guesthouse (dark atmosphere), we find ourselves preferring neither situation because we are under constant pressure. Yim Si Wan's repeated breakdowns just make us doubt when the breakdowns will actually happen.
The only downside that we can find in the series is that the protagonist could and should have left this boarding house after realizing the situation.
The end of the series is the last nail in our hard journey in this oppressive series with a plot twist that leaves us perplexed in front of our screen.