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