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: Test Of Humanity
Tear Jerker: Wheatley reduced to a near-suicidal depression in the middle of the story. Seeing the normally upbeat and talkative robot-turned-cyborg in such a state is rather heartbreaking.
GLaDOS torturing Wheatley by showing him clips of HAL (Which fuels his guilt regarding his former Face-Heel Turn) but replacing the audio with Wheatley's voice when he was evil and making it so that any pain he feels Chell will feel as well. It doesn't take long for Wheatley to be reduced into nearly incoherent sobs.