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