Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Nancy Drew
The historical back stories of the games tend to take a turn into the ridiculously depressing:
In Secret of Shadow Ranch, outlaw Dirk and sheriff's daughter Frances are in love. The sheriff finds out, Dirk gets hanged, Frances leaves Arizona forever without knowing about Dirk's final letters to her, and the sheriff dies alone, full of regret for driving away his beloved daughter. In fact, the paper his final diary entry was written on has stains left behind by the sheriff's tears.
In Danger by Design, Noisette Tornade, out of love for Paris and its art, employs the help of her German lover to steal and hide several pieces of beautiful stained glass so they won't be destroyed during World War II. When her countrymen discover her liaison with the German, they immediately accuse her of treason, and though she is acquitted and eventually becomes Director of Public Works in Paris, the suspicion against her never subsides and her lover is forced to leave her forever.
Treasure in the Royal Tower centers around the good intentions of Marie Antoinette. Guess how that one worked out.
Blackmoor Manor is sort of a Fridge Tear Jerker, when you recall how Jane's father talked about his father, and you realize that for roughly seven hundred years, the hidden rituals practiced by every other generation of the Penvellyn family have been causing its members to remain distanced from their own parents and children. All for a rock.
The historical backstory of this game is pretty sad as well. Rolfe Kessler, the titular carousel's creator, was in love with and married a woman named Amelia, but his personality was so intense and moody that she could not live with him although she loved him in return. They separated, he wrote letters to her and never sent them, and she died of tuberculosis without ever having reunited with her husband.
The backstory of Isis, the titular character of White Wolf of Icicle Creek, is absolutely heartbreaking. Her mother was shot by a hunter, and she was found by Julius Mc Quade, who got so tired of humans that he decided to live alone in the wilderness. He saved her life and discovered that she refused to leave him. He tamed (to some degree) and befriended her. Later he had to go to hospital and died there. Last words of his diary? "The possibility that she would think I abandoned her just breaks my heart. She has come to mean the world to me..." She probably felt the same way about him, since she kept returning to his cabin in search of him. In fact, that's where Nancy finds her.
Also the source of Fridge Tearjerker, when you realise that the reason why she sticks with Nancy is probably that she is looking for someone who could replace Julius, and Nancy is the only human who has been in his cabin since he died, so, maybe, Isis thought that she is somehow connected to Julius.
The overriding atmosphere of Thornton Hall isn't just fear- it's sadness. You never even meet Charlotte, but her death influences everything.
The argument between Carson and Kate in one of the flashbacks from The Silent Spy is particularly heart-wrenching when you know it's very likely the last conversation they ever had before Kate's death.
Nancy's letter to her mother.
Last Train to Blue Moon Canyon has yet another tragic historical plot. The train's owner, Jake Hurley, was a rich man who wandered through the Old West in search of gold - until he met the beautiful Frenchwoman Camille Voulet. They married, he commissioned a custom train to serve as their home, and they spent their time in happy travels. Then Camille fell, hit her head, seemed to recover, and died unexpectedly.