Early game spoilers ahead so please proceed on your own terms!
I recently finished Undertale by playing through the neutral route and later the pacifist route. The entire experience was awe-inducing to say the least and I finally understood why the game became so popular.
The moment that made me shed my tears was during the fight with Toriel. As I had taken up the pacifist route back then, I kept sparing her for all my turns and attempted to dodge her attacks. Eventually I was overwhelmed by her fireballs and brought down to 2 HP before I could get to skip the battle portion of the encounter.
When I proceeded to spare her as before and witnessed her taking her eyes off me and disarming her menacing expression, I started to experience a weird emotion. I braced my heart, barely hanging on to life, for another brutal round of attacks, only to watch all the fire projectiles begin to evade me, which only amplified this unknown emotion further.
That's when I realised what I was experiencing: sympathy for the protagonist and Toriel's unbounded and unspoken compassion towards each other. By "sparing" her for yet another round, the protagonist was declaring that they didn't wish to fight her, despite being brought to the verge of death by her attacks and knowing that they may not survive the next one. Meanwhile Toriel, possessing the ability to decimate the human along with sufficient motive to do so, ultimately couldn't find it in her heart as a mother to end their life as she went on to quietly express sorrow and guilt in her face afterwards while continuing to "fight". This scene of self-sacrifice and remorse was complimented by Toriel's fight theme song, resembling the tone of the tragedy of fighting a battle neither one of whom wanted to fight, ending up in a stalemate.
I don't know if there was something inherently unique about this moment, for some reason I immediately started shedding tears uncontrollably. It was as if this level of compassion and sympathy was untold of that overflowed my brain, ultimately making me feel sadness and happiness simultaneously. I ended up like this whenever I saw the screenshot of the fight or watched the recording of someone else's afterwards and eventually this moment became special to me. Even as I was writing this post, I happened to cry 3-4 times.
I don't know if someone else has had this experience before, either in this game or some other media, but if anyone does, I would really love to hear about it. Either way I feel like dumping this up here as an appreciation for the game dev for the wonderous journey the game made me go through.
Two games have made me cry, the first is the ending to Final Fantasy IX, the realisation of who was speaking the monologue at the end, and what that meant for that character was so well done. After 45+ hours with those characters, the emotional release, I was just bawling and I still had to go to school!
The other was What Remains of Edith Finch, which is an absolute masterclass in storytelling. Each scene in that game is a mini dark humoured tragedy of each of Edith's family members, that culminates in the revelation of Edith's impetus for this journey through her family's tragic history that she's now undertaking. In those final moments of the game, after only about 4 hours of gameplay, this game grabbed at my heartstrings and I was sobbing like a baby. My partner of the time asked what was wrong and all I could say was "it's just so sad!" Fantastic game, well worth playing even now.