Here is the full list of all 17 After Death achievements.
Get your first item from Ignaro
Meet all lost souls
Kill the final boss
Kill the real final boss
Open the Gate
Finish the game with less than 50%
Finish the game with 100%
Kill 50 enemies without any damage
Get the Ice armor
Get the Fire armor
Kill 10 enemies with only one scythe
Find all secret rooms
Activate all levers
Finish the game in less than 2 hours
Kill half of bosses
Destroy 50 projectiles with armor powers
Find one of the masks