Here is the full list of all 23 Serious Sam 3 VR: BFE achievements.
Complete the game in single player on unmodified serious difficulty.
Complete the game in single player in the estimated time on each level.
Awake the Guardian of Time.
Start the car.
Use the Mutilator to surf after a Werebull.
Blow a Major Biomechanoid into pieces.
Kill an enemy using the Mutilator.
Smash 20 Kleers with the Sledgehammer.
Power up the Timelock.
Kill a Witch-Bride of Achriman.
Kill 5 Cave Demons while they're in air.
Solve the riddle of the Sphynx.
Kill 20 enemies with the Minigun without releasing the trigger.
Defeat the spaceship.
Secure the bird.
Gib 20 enemies from close range with a shotgun.
Rescue professor Stein. So to say.
Find at least 10 secrets in single player.
Complete any level in single player.
Decipher an Egyptian text.
Kill at least 5 headless kamikazes in one explosion.
Complete any level in cooperative with at least 2 players.
Find Sam's classic outfit