Here is the full list of all 24 Lethal VR achievements.
Score your first headshot
Score a rating on every Round
Score a Bullseye with a knife
Perform your first Perfect with any weapon
Score a Double Bullseye
Score a Triple Bullseye
Score a Double Headshot
Score a Triple Headshot
Score a Quick Draw rating
Score a Fast Draw rating
Shoot a bullseye and a headshot into a single target
Perform your first double Perfect
Get 10 Lethal Ratings
Get a rating for the Beginner Simulation
Get a rating for the Amateur Simulation
Get a rating for the Rookie Simulation
Get a rating for the Recruit Simulation
Get a rating for the Agent Simulation
Get a rating with the Gold Plated Gun
Get a rating with the Dundee Knife
Get a rating with Harry's Gun
Get a rating with the Throwing Star
Get a rating with the Razor Tipped Hat
Get a rating with the OCP Gun