Here is the full list of all 12 BloodRayne Betrayal achievements.
Collect all the ancient vampire skulls
Complete the game
Finish every level with the ranking "Dhampir"
Hop on 50 heads in a row without touching the ground
Complete any level while taking no damage
Chain-explode 5 enemies
Kick open the Coffin Rocket 20 times
Find the hidden idol
Kill 5 enemies with a single gunshot
Defeat Crab Puncher without getting hit
Kill 250 enemies with environmental hazards
Activate BloodRayne: Betrayal's alternate soundtrack