Creator Backlash: Rob has bad memories of the experience, as he felt that Doug created the whole cosplay plot just as an excuse to get his legs fawned over, and he also had to deal with him having a "I've ruined everything" breakdown.
For Doug's part, he and Mickey regret the "goat fucker" joke because Fan Dumb never let Mickey forget it, even when Mickey asked that they let the joke die.
When things were going really terribly, Doug retreated to his bed to sleep all day and upon waking up, told Rob dead seriously that he was scared the cast were going to mutiny against them. And when Holly heard of what the boys were planning to do (scrap filming and make it a documentary), she was pissed and told everyone to meet at the hotel for another meeting, but Rob had to stall for fifty minutes to convince Doug that nobody hated him and he hadn't failed miserably so ball up and talk to everyone else.
After Elisa felt weak and dizzy from being taped to a wall, Rob wanted to go into the forest and never come back, thinking nobody would notice.
The Danza: Brad Jones as the Cinema Snob cosplaying as Indiana Jones.
In the commentary, it's revealed he rode the train to Chicago in costume, and arrived at the hotel asking "You have a reservation for Jones?" (and apparently the clerk didn't phaze a bit!)
The wedding dress Lindsay had on was really restrictive, and she had to sit down a couple of times because she had trouble breathing.
Benjamin makes it clear throughout his vlog that it was cold during filming, and he had to play his role as Conan shirtless.
Kaylyn cut her hair (and was not happy about doing so!) and made the costume herself (Doug even offered her to play Kiki instead, but she said "No way! I want to do this the hard way and make the HARD costume!").
And Iron Liz and Last Angry Geek as two of the Cloaks.
I Knew It: It was obvious to everyone somewhere late into the film that Ma-Ti is the only one to defeat Malachite, due to the "pure of heart" arc words repeated frequently. What viewers DIDN'T count on was Ma-Ti getting killed off!
Asserted repeatedly on William's Twitter that he couldn't make it to the shoot and wouldn't appear.
His wife blew the cover on her Twitter, but nobody noticed.
Jason did not go to Chicago for the special and never said anything about doing even a little cameo, not even a Twitter message about the special. On the day Part 6 was released, he finally revealed the role on his livestream.
Elisa's part was meant to be played by one of Rob's friends. Also, after Elisa nearly passed out from being duct taped to a wall for too long, the shot was discarded and redone with her taped to the couch instead.
Ed Glaser was supposed to be a Cloak, but due to weather conditions he chose to remain backstage and Iron Liz took over the role.
Spoony kept losing his hat, until it was turned into a deliberate Running Gag when he fled from the Cloaks. And again as a Throw It In when the Cloaks shot magic fireballs at him, the original idea was for it to barely miss him, but his movement caused the hat to tilt back and fall off, leading to them making the fireball knock it off. Eventually, he scrapped the hat all together.
He also ad libbed most of his attempt to use LARPing rules on the Cloaks (including "This power is beyond any of you!") as Doug asked him to do a more authentic reaction.
Todd ad libbed the "He looks like a member of Run–D.M.C." line, and was impressed that Doug decided to keep it. It made it into the trailer.
Crom's burp was done by Lord Kat as a joke - and the take ended up getting used!
Lupa got very cold during filming of the climax and started wearing her leather jacket whenever she wasn't filming, until everyone finally decided it fit the moment when she pulls out a gun.
Doug's sword broke during the climax, so he improvised trying to fight with the hilt and then stealing Mickey's sword.
An outtake of Tom immediately dropping Mickey while attempting the Fastball Special was considered funny enough to put in, with a line dubbed in that they're trying again.
The "Cloak 3, don't be a hero!" came because Iron Liz kept on "firing" while the others were retreating, and Heinz tried to remind her of walking back as well.
Joe's final attempt at My Name Is Inigo Montoya was supposed to be him finally getting it right; he ad-libbed messing up a different part.
Linkara declaring "Oh, screw this!" and pulling out the magic gun during the climax may be one of these; he can't remember if it was scripted.
Lupa was originally going to wear a black Snow White wig, but Doug decided it would be a crime to cover her strikingly red hair.
Orlando asked Doug if he could improvise what Malecite says on his cell phone amd Doug liked it so much that he didn't even film the scripted version.
Troubled Production: Doug and Rob had different visions on what kind of movie this would be and eventually made it more like a dramedy rather than a more straight-forward epic, with Rob turning into a ghost writer, fixing Doug's plotholes and clearing up some plot points at the last minute (Rob wanted it to be an actual tribute to Dungeons & Dragons and LARPing, while Doug wanted them all dressed in general fantasy costumes), weather was horrible during the 4-day shoot which prevented some appearances due to delayed flights and caused broken morale, some people dropped out because they wanted to spend Easter with their friends and family, and some glitches and general filming issues arose not too different from those that plagued Kickassia. The DVD documentary shows they nearly cancelled the thing, but everyone involved decided to give their best to finish it.
The whole Suburban Knights could've been completely ditched due to terrible weather conditions. In Benzaie's VLog, Doug thanks everyone for carrying on despite the cold and for helping him not give up.
MarzGurl was supposed to attack Malachite (fading daylight caused it not to be filmed) and Nella would be "the Chick's Patsy" (she couldn't get enough time off work and was reduced to a cameo).
The Brain vs. Luke sequences were originally going to incorporate Phillip and Ringo from Luke's Film Conscience reviews, but they were cut for time.
Bhargav was going to use a replica of the heart ring toy from the early 90s, but they had to use a normal pink ring instead due to the heart ring being the least popular one.
Paw's original character idea was King Graham, then Jareth (turned over to Jew Wario due to him already owning the costume. In the house scenes, you can see Paw wearing a David Bowie shirt).
Marzgurl revealed Doug offered her two costume choices, San or Kiki (specially because he thought the former's costume would be too difficult for Marzgurl to make... but she accepted the challenge).
Linkara's beard was supposed to last for the entire movie, but he went against it, worried that he wouldn't be able to get it off for the crossover videos.
Jew Wario was first written as Peter Pan, and suggested he be Jareth since it would be fun for the fans who'd seen his Labyrinth review, plus he already had the costume (there's no word on who Mickey would have been).
Benzaie pops out of Brad's legs. They considered having him coming from JarethWario's too.
The Witch Warrior sequence had the most rewrites. Originally the Witch Warrior was going to be a zombie named Mildred, who would bite Phelous and turn him into a zombie as well. Then she was changed to a witch who also had a mundane, corporate job on the side, and she would constantly be talking on the phone while fighting the team at the same time. They eventually went with a straight homely woman who suddenly became demonic.
During their belated Kickassia commentary, Linkara and Lupa suggest that the big gag with this would have been Lupa continually making princess-y demands of Lord Kat, specifically coming up with one where she asks him to put his coat over a mud puddle, and he replies "Just walk around it, you bitch!"
The alternate idea was "Piratesvs.Ninjas", where a Villain Team-Up (of Insano, Mechakara, Dark Nella, etc.) would become ninjas, defeat the TGWTG crew and then go after a magic medallion that could resurrect Blood Beard Joe (from Doug's "How To Be a Pirate" series). The reviewers then would train with Black Dog Bill to be pirates and go after them. It was scrapped because Doug thought it would only be cashing in a pirate and ninja fad, and also for his preferred BBJ actor, James Rolfe, being too busy. He hinted that elements of this idea would be postponed for the 4th year special.
Rob's commentary goes into detail on how Doug's original vision for the film was far more balanced between comedy and epic fantasy. The Troubled Production forced them to make it far more of a straight comedy.
Rob's commentary also revealed a much different opening segment, in which Malachite is sitting in on a Dungeons & Dragons game and ends up slaughtering the geeks playing because of the farce his magical heritage has become, establishing his hatred of gamers and his refusal to do the quest himself.
JesuOtaku and CR were going to appear but couldn't for schedule conflicts and personal reasons (JO speculated on the TGWTG forums what character she would have been after the fans brought it up, and CR still did the opening title cards for all the characters). They would finally make their TGWTG Anniversary debut in To Boldly Flee in parts that share scenes together.
Mechakara was originally planned to make a switch with Linkara in this special in order to try to find Malachite's Hand and take its power. The comedy would come from him having to play along with antics of the critics going on a fantasy quest. Linkara argued that Mechakara would rip everyones' throats out before even considering playing along with that. As such, the switch was saved for To Boldly Flee where Mechakara acted as a Knight of Cerebus and the only villain never Played for Laughs.
According to Rob's commentary, Doug tried to go a bit too far in the fanservice department, not wanting to wear anything under his mini-skirt, but Rob threatened to put a black censor bar over any good part and so Doug relented.
In one of the commentaries it's mentioned that there was going to be a small plot point about Malachite cursing Aeon's descendants to becoming stupider with each generation, culminating in Dr. Insano, but the idea was nixed cause Spoony didn't want to play him more than necessary.