Homer: Homer is one of the playable characters, he cam jump, kick, burp, turn into Homer Ball, "Heli-Homer" (only Xbox version), "Gumi-Homer" (only Xbox version) and "Lava-Homer" (only Xbox version).
Bart: Bart is one of the playable characters, he can jump, kick, use his wrest rocket, open his cape to release bats and turn into Bartman to glide, climb walls and ziplines and grapple. He can also turn into "Robo-Bart" (only Xbox version).
Lisa: Lisa is one of the playable characters, she can jump, kick, play her saxophone to stun enemies and uses the Buddha's Hand to pick up and drop big things, electrocute and freeze enemies. She can also turn into "Clobber-Girl" (only Xbox version).
Marge: Marge is one of the playable characters (only Xbox version), she can jump, kick and order her mob to fix things. She can also turn into "Police Marge".
Maggie: Maggie is not used by Marge in this level, but is always with her.
William Shakespeare: the writer now guards the Heaven's Gate. He attacks Homer and Bart by throwing explosive skulls. In the Xbox version, he floats on a cloud.
Reused Enemies: enemies throughout the level. They have appeared in other levels before, but now have halos on top of their heads due to previous defeats.
Lumbermen: from "Lisa the Tree Hugger". They attack by throwing wooden bits with their machines
Aliens: from "Invasion of the Yokel-Snatchers". They attack by shooting lasers or beating the character with wooden planks.
Dolphins: from "The Day of the Dolphin". They attack by shooting starfishes and flailing their tails.
Mob: these are the kids Marge can recruit to her mob. The same from "NeverQuest", presumably one of those sacrificed to complete the level.
Benjamin Franklin: the man who discovered electricity guards the gate to God's apartment. He attacks the Simpsons by attracting thunders with his key. In the Xbox version, he first turns into two smaller Benjamins, then into multiple smaller Benjamins until he is finally defeated.
God: He is the final boss. The Simpsons defeat Him in a Dance Dance Revolution game at His apartment.
Dance Dance Revolution characters: in the Dance Dance Revolution game, multiple characters from previous levels come in rows onto the arrows. These appear in the Praystation console.
Lumbermen: from "Lisa the Tree Hugger".
Zoidberg: from "Five Characters in Search of an Author".