Here is the full list of all 22 BloodGate achievements.
Complete 500 dungeons
Kill 2000 enemies
Max out 14 Warlock spells
Max out 13 Ironclad spells
Max out 13 Stalker spells
Collect 300 skulls
Unlock 14 Warlock spells
Kill 500 enemies
Kill Black Dahlia
Complete 100 dungeons
Unlock 13 Ironclad spells
Unlock 10 Warlock spells
Collect 100 skulls
Open 100 boxes
Unlock 10 Ironclad spells
Unlock 13 Stalker spells
Complete 30 dungeons
Kill 100 enemies
Unlock 10 Stalker spells
Collect 40 skulls
Open 20 boxes
Open 5 boxes