Too much is incomplete. Aeria always takes whatever files they get and shoves it into our game.
There's so many things that are worded badly or translated wrong. Those lazy people are too lazy to fix those minor issues.
Basically, a webcomic that posts one panel at a time with flash scenes thrown in like cutscenes in a game that are sometimes interactive. It also has its own instrumental soundtracks that have been released to go along with the story. It's long, but once I got past the somewhat slow start I devoured it in six days until I caught up. Some parts are set up so that you can choose which character you want to follow up on first, second, etc. before continuing the main storyline.
The youtube video sums up the story pretty well, using some of homestuck's music.