How canon-y is the game?

[Suskun Durgun]

I get that since this wasnt in the original ending its not fully canon (like the hs2 and other weird stuff) but hows the dialogue and situations? Do they feel too ooc and tainted with fanon or feel right?

[Netherin5]

Some people have complaints with the vriska route (I very disagree) but otherwise everything here is really excellent, handled better than the comic itself at times

[—I_Am_A_Floppy_Disc—]

I mean, its a product of its time obviously, so keep that in mind (2019). Regardless, I enjoyed the game a lot and don't think its too reliant on fanservice tbh.

[Rookie 1978]

Everything Homestuck related except SBaHJ and the original Homestuck webcomic are it's own kind of 'canon' seperate from the original content. The games, the sequel comic, the patreon comics for the sequel comic, even Andrew Hussie's own 'Word of God' commentary and later retcons are debatable at best.

While this is directly confirmed in a vague way by the epilogues and Homestuck 2, canon is what you want it to be, and everything outside the original Homestuck comic and everything it entails should be 'HEU', or Homestuck Extended Universe.

When talking about Homestuck, most people don't take products outside the original comic's scope into consideration unless they're explicitly mentioned.

So Pesterquest in a way ties into the HEU with a direct bridge to Homestuck 2, and also has some other ♥♥♥♥♥♥♥ going on, it kind of sets some stuff up that never matters, I don't know man. HEU is a ♥♥♥♥♥♥♥ mess.

At the end of the day, a more direct answer to your question:
Some characters have design choices that aren't in-line with the original appearances, and you'll be viewing a lot of 'artist interpretations' of characters that don't 1:1 line up with what's shown in the original comic in a myriad of ways. Characterization is undoubtedly tainted by fanonocity, but not to the degree that it feels disingenuous or too far removed from the source material to be enjoyable.

I'd say the characters are somewhat flanderized, sometimes to intentional comedic effect, but the general theme and tone of the characters are consistent. They still act in line with their comic counterparts overall, and it isn't enough of a culture shock to knock you out of whatever generic enjoyment you may get out of this game as a Homestuck fan that's read the entirety of the comic.