Just saw the most recent episode. Holy-moly it was great. The reveal it the end had me going "what?!?"
I'm really loving this show. Hirsch was right when he said it's influences were The X-Files, Twin Peaks and The Simpsons. I totally get all three.
Also, Schaal is a revelation as Mabel. The voice acting is great across the board, but she just knocks it out of the park. Hirsch himself is especially great as Stan and Soos.
Also for those who were looking for them here are the messages at the end of every credit sequence deciphered:
! Episode 1: "Welcome to Gravity Falls
Episode 2: "Next Week: Return to Butt Island"
Episode 3: "He's Still in the Vents"
Episode 4: "Carla, Why Won't You Call Me?"
! To get to this, take the "Three Letters Back" clue from the opening credits."
! My personal favorite is the reference to Larry King's Head
I agree with Luffy#1 Fan, I loved the continuity. The first 3 episodes all felt pretty stand alone, so it was nice to get an episode that contributed to the overall story.
One last thing, hopefully Linda Cardellini's role as Wendy gets expanded, because she's had like 4 lines total, and that's a waste of a great actress.