Plague and Treachery on the Oregon Trail

Susan: Did you just run over Baby?!
Cyrus: Son of a BITCH!

A Let's Play of Oregon Trail by Chewbot, who's known for also creating The Terrible Secret of Animal Crossing.

Cyrus Neckebard, a dimwitted banker, gets swept up in the patriotic dreams of the new frontier and drags his wife and children along on a family road trip to Oregon. Coming along with him is his promiscuous and unhappy wife Susan Neckebard, his piggish and hydrophobic daughter Sarah-Jane, his unusually black-skinned son Cyrus Jr. (AKA "Waffles" after the waffle incident), and Baby, a deformed infant born without a face who is of undetermined gender.

And it all goes downhill from there.

Notable for being interactive while he was making the story, including asking forum users on Something Awful to vote and choose what happened next, along with the names and personalities of the characters. Needless to say, Hilarity Ensues.

Can be found here.

Tropes used in Plague and Treachery on the Oregon Trail include:

Anyone Can Die: As is custom for the game series, to the point where they even had a betting pool over who they thought would die next and from what causes.
Aw, Look -- They Really Do Love Each Other: Considering they spend virtually the entire story hating each other, moments where they get along are usually a solemn Crowning Moment of Heartwarming.
Becoming the Mask: Susan initially married Cyrus as a cover, and pretended to be a happy family, only to find that she really does love him and their children.
Bittersweet Ending: Every one of Cyrus' family dies. But he made it to Oregon. And he decides to go on with his life and have many new adventures with the one ox that survived.
The Blank: Baby was born without a face. They never gave it a name, and no one ever bothered to see what Baby's gender is. Seeing as how its lived this long, they mostly just shove it into the corner like a sack of potatoes and ignore it.
Celebrity Resemblance: Chewbot insists that Waffles sounds exactly like Tracy Morgan's character on 30Rock, and writes his dialog as such.
Cerebus Syndrome: Once the family members start dying off, it gets much more dark.
Chandler's Law: The first edition Oregon Trail game is, quite frankly, boring to play and boring to watch. Hence why, whenever things get particularly dull, Chewbot gets a little... creative with his storytelling, like adding more Stuff Blowing Up
Convenient Miscarriage: Though everyone is too distracted by their newfound cocaine addiction to mind.
Determined Homesteader's Wife: Susan, who is not going to let a few broke limbs, bullets, or a medical book's worth of illnesses stop her from getting across the country.
Driven to Suicide: Baby attempts to crawl away from the wagon to suffer a more dignified death by being roasted in the sun and devoured by vultures.
Enforced Method Acting: While riding down the river, to simulate Cyrus riding while blind, Chewbot plays the minigame with his eyes closed.
Forgotten Fallen Friend: It doesn't take long for the family to stop mentioning Baby Neckebard, not that they really seemed to care much in the first place.
Functional Addict: When the family manages to get a hold of enough cocaine to fill an entire potato sack, they are happy, getting along, and one hundred times as productive than ever before. When they run out they don't so much go through withdrawal as much as they get frustrated that now they have to deal with each other sober again.
Gag Penis: Dongs McGee's "knife".
Genre Shift: About midway through it turns into a very, very different story.
Gonk: Sarah-Jane has a snout-like nose, and because she can't breath through her nose she has an obnoxious voice, and is frequently compared to oxen and pigs.
Happy Place: Every day Sarah-Jane hides under a blanket and tries to sleep and dream about a better place than her own life.
Her Child, but Not His: Waffles is black. Susan just convinced Cyrus that this is because he was born with a rare skin condition, and has nothing to do with why the only black guy in town laughs at him when he sees him. Given that his actual (still non-Cyrus) dad is white, she's telling the truth.
Ho Yay: It's implied one of the oxen might have had feelings for the other.
In Memoriam: After finishing the story, Chewbot released a music video dedicated to all the family members that couldn't make it to Oregon. It's actually almost pretty emotional.
La Résistance: Susan was part of a secret British organization bent on overthrowing America from the inside.
Let's Play
Living Prop: The Neckebards wouldn't quite consider Baby a part of the family so much as it is ... some kind of divine punishment, and its passing would be a mixed blessing for them.
Lower Deck Episode: Virtually an entire chapter was focused on the oxen discussing amongst themselves, while in the background the Neckebards are apparently having crazy adventures.
Miss Yo-Yo Knickers: Name a man. Any man. Susan's slept with him.
Mythology Gag: Cyrus stumbles upon a tombstone marked "peperoni and chease" and remarks that it must have been a child's grave.
Noodle Incident: The "waffle incident", as well as whatever was going on while the oxen were chatting.
Off the Rails: When Chewbot suggested the forum goons to vote via haiku (suggestions as to what to do next would be counted as two votes). They wouldn't stop posting new river crossing poems, even long after the voting was done and the results posted. Eventually they stopped haikus altogether and started writing full-length ballads and love songs based on the characters. Chewbot was flabbergasted.
- Updates 17 and 19 are when the story completely loses all handle on reality and turns into a high-stakes, explosive, bullet-riddled chase sequence, amongst several other unexpected plot twists.
One of Us: Forums user Der Metzgermeister, who performed most of the music in the LP and voiced Sarah-Jane in the last update, is troper Metz77
Punny Name: Cyrus Neckebard has one fine neck beard.
Rasputinian Death: All of the family becomes infected with many layers of deadly diseases that would kill a strong man in a dim hospital room, but this wagon full of feces-covered, emaciated lunatics crawling through a desert manages to shrug it off, to the point where they're all shocked when they do start dying.
Rock Bottom: No matter what happens, it not only could be worse, it will get worse. There's a reason why Chewbot nicknamed the wagon "the good ship hopeless".
Running Gag: "And that was when [blank] realized they hated their family."
Spirit Advisor: The ghost of Sarah-Jane aids Cyrus while he is riding down the perilous river.
Toilet Humor: Part 11 can really only be seen to be believed.
Tragic Dream: Sarah-Jane dreams of being an opera singer, but no one has the heart to tell her how disgusting the sound of her voice is.
The Dog Bites Back: When the wagon flips over in Snake River, Sarah-Jane immediately tries to drown her mother in retaliation for Susan doing the same to her as an infant and ruining her life.
The Un-Reveal: Waffles is just about to finally reveal the story of the waffle incident to Cyrus, only for it to be made very clear that he was just incredibly delirious at the moment from sickness, and none of what he said made any sense.
Video Game Cruelty Potential: So many members of the forum voted to ford the Snake River just to drown the whole family at once.
- Considering the obviously not-too-bright future of the family, this might actually count as Video Game Caring Potential.
"Well Done, Son" Guy: Waffles is this to Cyrus.
What Do You Mean It's Not Awesome?: When the decision came over what to do once they reached Snake River, Chewbot said he'd count anyone who posted their vote in the form of a haiku as two votes.

Think about it. What's more ridiculous than dozens of internet strangers voting on the river-crossing status of a fictional family based on an educational game that was created 30 years ago? Haiku about it.

Why Did It Have to Be Snakes?: Sarah-Jane has a fear of bodies of water. No, "fear" doesn't quite cut it. The very concept of crossing even a foot-deep river causes her to go into a screeching catatonic state. Needless to say, this problem comes up quite a few times for them.
You Can't Go Home Again: After nearly drowning in Snake River, Sarah-Jane can no longer return to the fantasy land in her head and pretend reality is the dream.