I refuse to stand up! / eating ice cream
Something isn't right. At one point, Stan says he can't find the remote and he refuses to stand up. But later, he is suddenly eating ice cream. If he refused to get up, he wouldn't have been able to get the ice cream. Is someone in the house with him? This stretch of an explanation falls apart when you consider that he didn't want to watch the movie, and was calling out to the kids to have them change the channel.
The future is in the past!
The most commonly accepted theory here is that this is a reference to the future episode "The Time Traveler's Pig", in which the future was in the past.
Arrows in the wrong places
I just found it interesting that the arrows in this game came down in the wrong places once Thompson was sucked into it.
Lee in Lee's cereal
I also found it interesting that the cereal Lee was trapped in was called Lee's, as if it was foreseen that Lee would be trapped in it.
inescapable maze
On the back of the box of Lee's cereal, there's a maze, with the headline "Can you escape?" The answer is no. It is actually impossible to escape from this maze. It's a reference to how the teens would not be able to escape from the convenience store.
Robbie disappears
While Dipper and Wendy were hiding and the rest of the group had received their fate, Robbie seems to have disappeared. It's not unlikely that he did in fact disappear, being connected in some way to the anomalies of Gravity Falls. This seems to be further support that he's a zombie, or maybe a vampire.
Dusk 2 Dawn
The name of the convenience store is Dusk 2 Dawn. At the beginning, it seems to be foreshadowing the ghosts that live there; ghosts traditionally come out only at night.
Onwards Aoshima!
