(Copied for Wikipedia) Homestuck, the latest and ongoing adventure, began on April 13, 2009, and follows four teenagers as they play a reality-altering video game that brings about the end of the world, its basic premise being inspired by games like The Sims, Spore and EarthBound.[2] As in Problem Sleuth, the adventure is characterised by time travel, mystery, a complex fictional universe and frequent references to pop culture and previous adventures.

In shorter words: This is an MS Paint Adventure based on 4 teenagers who play a reality altering video game.