In the demo version of Afterlife, a low grade gluttony punishment was named "Taco Hell". In the full retail version, the same punishment was called Taco Inferno.
When Hell is suffering from a "Disco Inferno", the planet between Heaven and Hell is temporarily replaced with a Disco Ball.
Typing the phrase SAMNMAX (capitals required) three times will cause Sam the Bunny from Sam and Max Hit the Road (1993), an earlier Lucasarts game, to stomp around Hell.
The "Bats out of Hell" disaster is not actually a 'disaster' at all. When a structure has Bat Guano on it, it emits Very Bad Vibes - exactly what Hell structures need to grow into better structures. Many players do not put the first "prize" structure into Hell, specifically because it destroys the Bats.
Zoning a 7x7 grid in a certain manner unlocks the Mother Shak, with a hidden message about spirituality by the game's lead writer Michael Stemmle.