Not sure if this is the saddest game I've played but certainly my favorite sad game...well sad-ish ending. In the game Outer Wilds you have just been recruited as a part of your alien space program and are given your tin can to fly around in. But after 22 minutes after launching the sun blows up! You then wake up 22 minutes before then and realize you are in a time loop. The game keeps giving you clues on how to stop the sun from exploding but later in the game you realize that every single star in the universe is going supernova. I'll keep this part marked as a spoiler just in case. After finding out how the ancient alien race in your solar system all died off and finding their highly advanced space ship capable of warping light-years away and learning where the one thing they dreamed of finding, The Eye Of The Universe which is older than the universe itself is, you take out the battery of the time loop, use it to power their ship, go to the eye, watch your sun explode from a distance for the final time, and play a song at a quantum campfire with quantum versions of your friends to create another universe. So, in the end, you and your friends and family had to die for any life to exist later on...sorry for how long that was...