Just a few non-crucial glitches left that I found in my full playthrough (Thank you SO much for all of your hard work-- Videlectrix makes some of my favourite games ever), in-case you might want to know:
If your cursor is centered on the "down" brick on the KOT's castle, you can't click it. All the other bricks don't have this hotspot problem.
If your cursor is centered on or at the top of "Inside Bubs'", you get no hotspot. Don't know if that one's intentional or not. Just figure it'd make sense to have it be the whole inside of the door, or at least function if the cursor's dead-center.
When I decided to use an object on the secret X, I ended up looking away from the Goblin as I talked with it. Dunno if that was just a freak accident or not.
If you descend the ladder from the Spooky, Leafy Tree, and try to use an item on the tree without moving at all from the place you were spawned, Homestar's talking animations don't play. This didn't happen in any other area where I descended or ascended a ladder.
And finally, if I click on the Exhaust Pipe after pouring the Strong Mad Oyster Smoothie Breath Caked Armpit Latte doone it, the "Meh!" sound effect plays again, but no subtitle goes along with it.
Rock-rock on, and hope I'm not just boring you. Just love this game! (Last aside: during this playthrough, I noticed that Homestar repeating, "Busted his head, man..." had a similar schoolyard banter quality that Hector & Kovitch dialogue has. It's a leathew glove, man.)