A game about a murderous AI's inability to address its feelings and move on from a toxic co-dependant relationship.

So much emotion in the ending, partly from the thrill of the escape, but GLaDOS' song is genuinely heartbreaking. Her arc from wanting Chell dead to simply out of her life pack a real punch.

I found the entire second half of the game and its lifeless depths of a long abandoned facility incredibly depressing as hell. Just thinking of all the lives that went into constructing each area, placing each sign; each terrified and victimised test subject; all the souls that once occupied this site, now forgotten. All that's left are rusted remnants of an industrial scientific horror-house.

I don't know. I can't help but think it's one of the best games about regret and death.