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