Something to help visualize the scope of Homestuck as a single work with four parts.

Top-left: Part 1 (Act 1 - Act 4), focusing on the Earth and characters of Universe B1, the “Beta Kids.” The trolls from Universe A are present in the background, but focus generally goes to their effects on our universe. (Image taken directly from the end of Act 5 Act 1)
Bottom-left: Part 2 (Act 5), focusing on Alternia and the trolls of Universe A2, the “Beta Trolls.” Their motives, and the long-reaching influence of Alternian culture, define much of the content in the comic. (Image also taken directly from the end of Act 5 Act 1)
Together, the left side of the image comprises Side 1, the maximalist/mechanical half of Homestuck which focused on the relationship between humanity and the trolls that created us. As the main characters dove into fantastical and abstract worlds to act out their conflicts, they left behind the physical planets they had overlooked, passing the buck onto their Guardians, Exiles, and late-game constructs, some of whom are manipulating a very long and dangerous game.

Top-right: Part 3 (Act 6 Act 1 - Act 6 Intermission 5), focusing on the Earth and characters of Universe B2, the “Alpha Kids.” The cherubs from Universe C are present in the background, but focus generally goes to how they’re affected by what happens in our universe. (Image taken from the start of Act 6, with the Green Sun imposed on by me.)
Bottom-right: Part 4 (Act 6 Act 6), focusing on the cherubs of Earth C that will exist and the dramatic cosmic cycles necessary to decide who will inherit the Universe. The cherubs’ games, and the eternal return of juju-fuelled “Retcon” callbacks, define much of the form of the comic. (Image taken from Act 6 Intermission 5, with the Abstract Sun imposed on by me in such a way that it also kinda looks like the Yaldabaoth platform.)
Together, the right side of the image comprises Side 2, the minimalist/artistic half of Homestuck which focused on the relationship between humanity and the cherubs we will create. As the Guardians (now kids), Exiles (now empowered), and late-game constructs (now awake and talking) engage in longer delicate systems for maintaining reality, the main characters get a chance to be overlooked and get lost in purgatories of thought, some of which are manufactured by nearly-forgotten hubristic specters.

EDIT: OH FUCK THAT’S RIGHT, the image can also be split horizontally

Together, the top-left and top-right form the “standardized” and most MSPA-like Earth parts, focusing on the base– the present (from two different angles).
Together, the bottom-left and bottom-right form the “experimental” and most distinct parts, focusing on the extremities– the past and future.

And if you’re wondering about the significance of diagonal pairs (top-left + bottom-right, bottom-left + top-right), those are the pairs that are actually connected in the story (Cascade/Intermission 2/Act 6 can be seen as where the “snake” of Side 1 bites Side 2′s tail, and Collide/Act 7/Credits is vice versa). They aren’t connected that way in this image, but that’s okay, as that particular kind of connection wasn’t the point of the image.

OKAY. That should be all. Anything else, I leave for you to interpret. It may take me a while to get to the point, but Homestuck taught me it’s okay to take it slow if you need to.