Here is the full list of all 30 Disgaea PC achievements.
Completed Final Episode of Etna Mode "Chronicles of Etnarnia"
Completed Ep. 1 of Etna Mode "Super Dimensional Etna"
Completed Final Episode "What Lies Beyond the Battle"
Dealt 10,000,000 Damage!
Performed 10 transmigrations
Defeated all EX bosses!
Completed Ep. 10 "Angels, Demons, and Humans"
Defeated the Extra Boss "Baal"
Defeated the Extra Boss "Priere"
Defeated the Extra Boss "Item God 2"
Obtained the Hyperdrive!
Defeated the Extra Boss "Item God"
Defeated the Extra Boss "Item King"
Defeated the Extra Boss "Marjoly"
Obtained Total LV 10,000
Obtained Total LV 1,000
Obtained Total LV 5,000
Dealt 100,000 Damage!
Obtained 10,000,000 HL at the end of battle
Cleared Extra Stages "Cave of Ordeal"
Performed your first transmigration
Obtained the Dream Hand!
Obtained 1,000,000 HL
Obtained Total LV 100
Killed 1,000 enemies!
Completed Ep. 5 "Etna's Secret"
Completed Ep. 1 "Prince of the Netherworld"
Killed 500 enemies!
Defeated the Extra Boss "Item General"
Killed 100 enemies!