Billy and Mandy's Big Boogey Adventure is a much more light-hearted romp compared to Wrath Of The Spider Queen, but the way the film sets up its larger story at the beginning with a bad future sequence and the song "Land Of The Dead" by Aurelio Voltaire as the movie's intro is very impressive. One of my favorite moments from the beginning of the film is the chase scene with General Skarr, as it is fast-paced, has a few funny moments, and introduces newer viewers to the main trio without needing to see prior episodes.
Boogey feels like a much more realized character here compared to his debut in "Bully Boogey". While he is an unlikable jerk towards Grim, I feel that he fills his role as the film's villain quite well. One thing I like is how the CGI elements, such as Boogey's pirate ship, blend in nicely with the 2D visuals. It looks great and gives the backgrounds lots of detail. Kuki Sanban, also known as Numbuh 3 from Codename: Kids Next Door makes a few appearances within the film's story, and she doesn't feel tacked onto the plot.
From this point on, we get some fun scenes, including Grim's Stages of Grief over losing his scythe, and the song, "Scary-O", performed by Billy. While I like the song's Ziggy Stardust reference towards the end, and it is catchy, I feel that older viewers will get tired of it pretty easily due to Billy's singing voice sounding more annoying than his speaking voice. We also see a dream seqence when Billy-Bot and Mandroid make the trio plus Irwin fall asleep after eating cake, but I find this scene to be dragged out and uninteresting.
After this, Boogey kidnaps Mandy and the group set out to save her, with Irwin becoming buff and changing his outfit for the rest of the film. While I do like his bravery, I'm not a fan of his crush on Mandy as a whole, since I think Irwin is a better character when we're getting introduced to his mysterious family members in the main show. Soon after Mandy is saved, Billy gets taken by a Kraken that Boogey summons to hinder the gang. For a moment, Mandy is actually worried about Billy's wellbeing, and almost tears up before the Kraken brings him back a few minutes later.
Now we see some of the film's best sequences in the Cannon-Ball Run. From the group working together to overcome the race's obstacles in different ways (ex. Grim using his cloak as a parachute to make the boat fly over a large gap, Billy using his snot to put the boat back together after it breaks in four pieces), to seeing the characters turn into puppets for a quick gag, the Cannon-Ball Run is a very fun and thrilling watch.
When the group reaches Horror, we get to see their true fears come alive. Billy's fear is kind of frightening, as it involves him being attacked by a Spider/Clown/Mail Carrier monster. Irwin's fear has him being surrounded by bears while performing on stage. Mandy's fear is quite disturbing, as it involves her meeting an older version of herself who has a positive outlook on life, and to her disgust, has married Irwin. But we also learn that Grim's fear is already taking place in his daily life by having to live with Billy and Mandy as their "Best Friend Forever". This makes Grim's hatred of the kids all the more real, as he feels pushed around and burdened by them ordering him to do their chores and ending up in bizarre situations that they struggle to get out of.
At the film's climax, we see Boogey get defeated by Grim turning off Horror's Hand, making his goal to become scary again fail spectacularily. We also see that Billy-Bot and Mandroid have turned against Boogey, and that a version of Billy from a bad future has come to warn the group about what would happen if Mandy got ahold of Horror's Hand and used its powers for herself. Because of this, the group decides to store Horror's Hand inside Grim's trunk, so it doesn't end up in the wrong hands. After the film concludes, we see what happened to the cast of characters after the movie's events as "Boogie Wonderland" by Earth, Wind, and Fire plays. Some of these pictures are quite hilarious, and it ends the film on a high note.
