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