Level 6 takes place on October 30; interestingly, the day before Halloween. To add to the foreshadowing, the moon appears gigantic in a near purple sky, with Buzz Cola pouring out of valves at the Squidport. This is part of Kang and Kodos' plan to bring Foolish Earthlings back to relevancy. Bart and Apu know this, but Apu is too afraid to do anything, so Bart goes solo. He manages to put a huge dent in the alien plan, which includes destroying the free laser gun stands, disposing of crates of laser guns, and getting the word out to Krusty, a major player in the public TV sector.
Level 6 is set at the Squidport again and reuses the same map as Level 3 apart from with a few modifications: Instead of taking place at dusk, the level takes place right before midnight. As the newspaper suggests, the Squidport is completely redesigned to celebrate the complete displacement of Springfield's water supply with Buzz Cola (banners and balloons have been decorated all over). Any natural body of water in the map, including the background water, is completely contaminated with the drink.
Two vehicles are replaced transitioning from Level 3 to 6. The Compact Car and and Pickup make it to Level 6, but the Fish Delivery Truck and the Sports Car A are replaced with Burns Armored Trucks and Itchy and Scratchy Movie Trucks. Also replaced is the gigantic screen with Mr. Burns' face on it in front of the ramp at Burns' Casino. Instead, two hoops occupy the space immediately after the jump. The first hoop is on fire, while the second one has icicles hanging down from it.
The music that plays in this level is the same music that plays in Level 2.
- Going to the Lu'
- Getting Down with the Clown
- Lab Coat Caper
- Duff for Me, Duff for You
- Full Metal Jackass
- Set to Kill
- Kang and Kodos Strike Back
- Bonus: Milking the Pigs
- Ferrini - Red (Starting vehicle)
- Globex Super Villain Car (Purchase from Kearney for 600 coins)
- Bandit (Bonus Mission)
- 36 Stutz Bearcat (Street Race prize)
- Armored Truck (Purchase from Gil for 400 coins)
- Chase Sedan (Purchase from Gil for 500 coins)
Main Article: Wasp Cameras#Level 6
Main Article: Gags#Level 6
- Robot with the knife in the back of the Android's Dungeon.
- Radioactive Man cardboard cut-out in the Android's Dungeon.
- Yellow dumpster across the street from the Krusty Burger by the Android's Dungeon.
- Ball drop at Wall E. Weasel's.
- Crane on top of the C. Spanker.
- Alarm at the Observatory.
- Perpetual motion machine on the desk at the Observatory.
- Telescope at the Observatory.
- Monkey in the matter transporter at the Observatory.
- Flag at Kamp Krusty.
- Boar's head at Kamp Krusty.
- Main article: Level 6 Collector Cards
- This is the last level of the game to feature Bart and Apu in the main story. It is only during Level 7 that Bart and Apu can be seen driving their cars (Honor Roller, Ferrini - Red, and Longhorn, respectively) when they are accessed through a phone booth.
- This is the last level that the street races are hosted by Milhouse, Nelson, and Ralph as in the next level, they are hosted by zombies. This is also the only level where two of the street races vs. an opponent were only one-on-one instead of vs. any other extra opponents.
- The most expensive clothing in the game is bought in Level 6, along with the most expensive car that is not bought from Gil.
- It was originally intended that two Chase Sedans would chase the player in the event that they got a Hit & Run instead of police cars.
- In early builds of the game, the sky background for the level had a larger moon, more noticeable clouds and a less vibrant Maroon color. This background is interestingly used as the background of interiors in the level itself in the final game as well as in the level's bonus race course.
- In the level's cutscene, there are a couple of differences around the Duff Brewery which can also be seen in early screenshots of the game:
- The sky has more noticeable clouds and a less vibrant Maroon color like how it did in prerelease versions of the game.
- There are four duff wagons around the brewery parking lot, with the fourth being parked beside the entrance.
- The three large boilers where the duff beer gets poured into from the pipes are taller and larger, and are connected to the pipes.
- The drive-through garage at the side of the brewery that leads to the area with the duff blimp is shut-off with a garage door, and the Krusty Glass is missing.
- There is a more bigger gap in between the side of the fence at the brewery's entrance and the building itself for the fourth duff wagon to be accommodated.
- The two beer statues situated at both ends of the brewery parking lot have a purple-blue hue.