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.
YMMV: Friendship Is Optimal Always Say No
Nausea Fuel: To say that the state of several of the survivors Greg encounters is not pretty would be a gross understatement.
Nightmare Fuel: The state of Earth. One can hardly blame most of the remaining human population for emigrating to avoid it.
Tear Jerker: Katie's death, right after she saves Greg's life.