Andrew Hussie started off playing a forum game called MSPaint adventures where he drew something in an unpolished style (not actually in MSPaint lol) and basically played an improvised 90s adventure game where the next action was decided upon by people in the forums. Usually reasonable suggestions to overcome a problem resulted in disasters, and the weirdest suggestions end up being right.

Homestuck started out as a forum game but Hussie eventually stopped taking suggestions and just did his own thing at a point, but it's influential on the style.

The story focuses on long distance friends who get stuck in their houses cause of magic or something and have to find a way out, using adventure game logic. You learn about their lives and families and such. There's a lot of long conversations that read like AIM and jokes about inventory systems. The plot gets increasingly more convoluted, the cast cycles a few times, and characters that started off as simple jokes gain dimension.

I eventually stopped reading because it got too much for me but it's a cool thing. I hope this helps lol