I knew it; I was even right all four times. So how did you guys get Edwin Tiong (aka Omahdon) involved? Did he come to you or vice versa?
I put out a casting call for voice auditions and most of the voice actors came to us. I simply chose the actors I thought were best-suited for each role. I must admit, I love bringing this part of the game together. It's a lot of fun! Edwyn Tiong was one such voice actor who responded to the casting call and nailed the characters I'd asked him to send audition takes for.
Any other interesting stories about the various VAs in the game?
Robert Adamson who plays Gwydion/Alexander used to correspond with me back in the days when we released KQ1VGA and KQ2VGA, before he started landing roles in Hollywood. He generously offered his services for the role, and we were happy to accept them!
Sara Blaine who plays Rosella is also a professional voice actress who's provided voices in Pixar/Disney stuff. She's voiced characters in several Sierra games as well. She requested that we use a pseudonym rather than her real name, as she didn't want SAG to find out that she did the role.
John Bell plays both the Narrator and Manannan. I was worried that people would think the two voices sound too similar, but there seem to have been no complaints (that I've heard). I also raised the pitch of his Manannan voice ever-so-slightly. It was a hard role to cast because it required an older male actor and those are harder to find on the Internet. I also didn't want to go with a 20-something person impersonating an old man. Manannan plays an important role in the game, so he had to sound authentic. It seems he pulled it off quite well, as most people like the way the wizard sounds. Oh, and he also plays The Pirate Captain too. (Incidentally, I played the First Mate, so the Captain and First mate back-and-forth dialogues are between the same 2 people who voiced Al Emmo and the narrator dialogues in The Lost Dutchman's Mine

)
Caroline O'meara who plays the barmaid, is my cousin.
Josh Mandel was an obvious choice for Graham. However, his microphone produced such loud background noise, that after 5 attempts he had to end up getting his lines done in a proper recording studio. The things Josh does to entertain his fans!
Sean V. Crisden is super talented and adjusting his voice to suit the role. Off the cuff I asked him for an "Iago impersonation from Aladdin" for the seagull, and he pulled it off flawlessly. He also played the Monk in the retake lines we did for KQ2VGA.
Corey Cole was originally meant to play George Behr, Lori was going to play Mildred Behr, and I beleive Sean wanted their son to play Baby Behr. But it was difficult to arrange, so only Lori ended up recording lines and she ended up playing Smaude instead. She based it somewhat on her Queen Icebella role from King's Quest V.
Al Lowe declined the role of the Bard cum Minstrel.
Richard Aronson who played Count Caldaur in Romancing the Stones (and Cedric in KQ5) was orignally recorded and lip-synced for Seran. In fact, his lines were still in the game up until a couple of weeks ago. I made the difficult decision to cut them, as the audio quality was too poor when compared to the other actor's recordings.
Bob Noble re-recorded Seran's lines.
Kira Buckland who played Midred Behr and the bluebird has been in a few things.
Rachael Faught (Valanice), Josh Mandel (Graham), the Narrator (John Bell), The Father (TamTu Bui), and me (Gnome) are voice actors who returned to this game to reprise the same character roles they played in either KQ1VGA or KQ2VGA.
We tried to get Robby Benson involved, but his agent wanted a million dollars or some crazy figure. I swallowed.
Some of the credits are now listed on IMDB (I guess they are still in the process of adding the rest):
http://www.imdb.com/title/tt1847623/