Disgaea: Afternoon of Darkness:
Changes from the original:
- 16:9 format to take advantage of the PSP's widescreen display.
- Alternative narrative with Etna as the protagonist.
- Some extra boss battles such as Overlord Zetta from Makai Kingdom and Rozalin and Adell from Disgaea 2.
- A multiplayer mode available through Ad-hoc connections.
- A music shop and a record keeper were added.
- A complete dual language option and the option to turn off battle animations.
- Most of the silent Japanese cut scenes now include voice acting.
- Added geo Cubes, magic items that add more depth to multiplayer battles.
A port of the PSP release "Afternoon of Darkness". Changes from the PSP port:
- The option to toggle between English and Japanese dialogue, and many additional voiceovers were dropped.
- Added demon gadgets, randomly generated items that appear on the battlefield. Units can power up by acquiring these gadgets.
- New unlockable characters from the original Disgaea, Adell and Rozalin from Disgaea 2 are unlockable as hidden bosses within the Cave of Ordeals, as well as the Dark Assembly guide, Pleinair. Overlord Zetta also debuts as an unlockable, playable character.
A port of the PSP release "Afternoon of Darkness":
- All PSP features present.
- A later patch added the four characters previously exclusive to Disgaea DS.
An anime series based on Disgaea: Hour of Darkness entitled Makai Senki Disgaea (literally Netherworld Battle Chronicle Disgaea) aired in 2006. Consisting of twelve episodes it follows the general plot as Disgaea: Hour of Darkness but with several alterations to character roles and the chronology of events.