I'll keep this review short.
If apocalyptic movies and dramas are of your taste, you've probably watched many of the popular ones out there, including Sweet Home (which is also getting a S2 very soon). While watching All of Us are Dead, many of the scenes had me thinking back at Sweet Home's plot. The plot is so overused and repetitive ;-; I would just recommend that you go watch Sweet Home if you haven't yet/if you're looking for a good apocalypse drama, cus this isn't it. The casts carried this drama imo, esp the male lead.

TLDR
If you're looking for a good drama, go watch Sweet Home instead. They invested way more into that drama and the CGI is insane. Not up to par to this drama.