Flo Lieb’s review published on Letterboxd:
As to be expected after the massive hype this is not the masterpiece it's made out to be. Yet I'm in general not Bong's biggest fan, even though I'll concede that his take on classisim here works better than in his underwhelming Snowpiercer.
The premise of the nesting Kims is neat and at times amusing which makes the first half rather enjoyable. There seems to be a natural path to be taken narratively to steer this into Korean cult movie territory amongst works like Oldeuboi and Bong even sets this path up rather well nuanced but then (as he so often does) drops the ball at the end of the second act.
Where the movie goes in its third act might seem inventive yet I personally would've preferred a different and probably more interesting direction [at least for me] that probably would - in addition - also have added to the classism theme. But maybe you would need a director like Park Chan-wook for something more extreme like that.
It doesn't help that the film is way too long (runs two but feels three hours and could easily lose 20-30 minutes). But the direction and cinematography are quite good (better than the screenplay) and the cast is convincing for the most part (Song kills it as usual but Park So-dam and Choi Woo-shik struggle at times). It's a shame that some of the characters like Mrs. Park are disappointingly bland and one-dimensional.
Conclusion: could've been great and ended up being alright.