These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crosses the Line Twice: While generally the Black Comedy is more subtle, there are a few moments that fit into this trope. Some good examples would be Drake's death, in which he repeatedly gets stabbed with multiple objects as his killer tries to pass it off as an Accidental Murder, only to continue and rant about how "Would you just die already? This is hard enough for me!" and Zee trying to have sex with Felix... on the same bed where his dead mother is laying (he is considerably freaked out).
And the ending where after shooting Erin, thinking she's killed everyone, the one cop who finally arrives goes through the front door, only to fall victim to the axe trap Erin set earlier before cutting to the title of the film splashing in blood.
Hype Backlash: With a two year wait and the promise of being something truly new and original, this was bound to disappoint some people. Its novel ideas are simply that the Final Girl be a distaff John Matrix and that the gore-fodder all be direct family, which automatically heightens the emotional stakes. Other than that it's a very straight-up example of the genre, albeit well-executed.