Choices and the ending of the game depend on in-game decision's by the player.
"In six days, every single living cell on Planet Earth will be dead." This quote sums up the plot of the game. To elaborate, a group of scientists have six days, and one chance, to save the planet from a "beyond deadly" virus, known as E48K15. E48K15 was originally known as the cure to cancer, which was discovered, on Monday, by the previously mentioned group of scientists. The group is lead by John Pilgrim, the protagonist of the game. After E48K15 is found to be deadly, the group has their funding pulled, one of the scientists commits suicide, and an overwhelming percentage of the population, including most of the scientists, die.
John Pilgrim: John Pilgrim, the protagonist of the game, and the leader of the group of scientists that discover E48K15, originally known as the cure to cancer.
Penny Pilgrim: John Pilgrim's wife. On Friday, the fourth day of the game, Penny is found dead in a bathtub full of blood.
Molly Pilgrim: John & Penny Pilgrim's daughter. Molly is one of what is assumed the final survivors of the E48K15 virus. The other survivor being, John. While going to the park is an in-game decision on Saturday, PewDiePie decides to go to work. However, on Sunday, after the a cure to the E48K15 virus is discovered by John, Molly and John sit on a park bench. It is assumed that they were the final two survivors. When PewDiePie refreshes the page, Molly and John are no longer on the bench and the plants go from being brown to a healthy green.
Jim: A doctor who is smoking outside of John's workplace.
Boss: Assumed due to his name, he is John's boss. Boss is also a member of the group of scientists.
Annie: A female scientist who is nicknamed "Miranda" by PewDiePie. She offers to skip work with John after E48K15 is discovered and still thought to be a cure to cancer, but PewDiePie chose for John to decline. Later in the game, after E48K15 had already been discovered to be deadly, she offers again, citing "this could be our last day on Earth." PewDiePie once again decided for John to decline.
Matthew: A male scientist who is nicknamed "Estefan" by PewDiePie. He jumps off a building, committing suicide, on the day that it is discovered that E48K15 is deadly.
Ryan: A male scientist who gives John the keys to the lab, allowing John to work on a cure to E48K15.
President: The President of the United States, resembling real-life U.S. President, Barack Obama. The President is seen next to Boss and John, and later in a newspaper article, by himself. He is one of the world leaders who addressed their nations, telling them of the "up and coming 'end of days'."